Qualification: 
Ph.D, M.E, BE
n_radhika1@cb.amrita.edu

Dr. Radhika N. currently serves as Associate Professor at the Department of Mechanical Engineering, Amrita School of Engineering, Coimbatore. Her areas of research include composite materials, metal matrix composites, functionally graded materials, optimization techniques, heat treatment process and tribological characteristics. She has published more than 40 research papers in reputed international journals. She is guiding B.Tech, M.Tech students and research scholars in her core areas.

Education

  • 2012: Ph. D. Mechanical Engineering
    Anna University
  • 2002: ME Engineering Design
    Kongu Engineering College, Perundurai.
  • 2001: BE Mechanical Engineering
    VLB Janaki Ammal College of Engineering & Technology, Coimbatore.

Professional Experience

Position Held Institution Period
Associate Professor Amrita Vishwa Vidyapeetham, Coimbatore July 2015 to till date
Assistant Professor (Selection Grade) Amrita Vishwa Vidyapeetham, Coimbatore May 2012 to June 2015
Assistant Professor (Senior Grade) Amrita Vishwa Vidyapeetham, Coimbatore July 2009 – April 2012
Senior Lecturer Amrita Vishwa Vidyapeetham, Coimbatore July 2007 – June 2009 
Lecturer Amrita Vishwa Vidyapeetham, Coimbatore June 2006 – June 2007
Lecturer Karunya University, Coimbatore September 2004 – June 2006
Lecturer Velammal Engineering College, Chennai June 2003 – September 2004
Research Associate Kongu Engineering College, Perundurai June 2002 – December 2002

Research Contributions

Thesis

Investigations on Wear, Machinability and Tool Condition Monitoring of Hybrid Aluminium Composites

Reserach Area

  • Composite Materials
  • Metal Matrix Composites
  • Functionally Graded Materials
  • Optimization Techniques
  • Heat Treatment Process
  • Tribological Characteristics

Sponsored Project (on-going)

Lab Established

Established -Tribology Research Laboratry under Department of Mechanical Engineering with the project support from DST and DRDO

Reviewer for International Journals

  • Journal of Particulate Science and Technology
  • World Journal of Engineering and Physical Sciences
  • Tribology-Materials, Surfaces and Interfaces
  • Journal of Mechanical Science and Technology
  • Journal of Industrial Lubrication and Tribology
  • Journal of Engineering Science and Technology
  • Engineering Science and Technology- an International Journal
  • International Journal of Materials Research
  • Tribology Letters
  • Transactions of Indian Institute of Metals

Editorial Board Member

  • International Journal of Composite and Constituent Materials
  • Journal of Mechanical and Mechanics Engineering
  • International Journal of Manufacturing and Processing

Publications

Publication Type: Journal Article

Year of Publication Title

2018

Dr. Radhika N, Reghunath, R., and Manu Sam, “Improvement of Mechanical and Tribological Properties of Centrifugally Cast Functionally Graded Copper for Bearing Applications”, Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, 2018.[Abstract]


The functionally graded Cu-11Ni-4Si/10wt%WC composite and its alloy have been synthesized using horizontal centrifugal casting technique to compare the mechanical and tribological improvement and its utility for bearings and bushes. Microstructure analysis and mechanical tests showed 43% improvement in hardness and 160% improvement in tensile strength at inner radial distances compared to the outer composite periphery. Fractural analysis showed ductility for alloy, whereas for composites, brittleness at outer and a combination of both ductility and brittleness were observed at inner. Proportional rise in the wear rate and coefficient of friction was observed with increasing load and sliding distances for both composite and alloy. Composite showed a slight decline in the wear rate and coefficient of friction with an increase in the sliding velocity, while alloy showed a linear rise. Worn surfaces analysis of composite showed the formation of oxide layers, which reduced the coefficient of friction at higher sliding velocity, resulting in lower wear rate.

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2018

Dr. Radhika N, “Comparison of mechanical and wear behavior of Al alloy with homogeneous and functionally graded silicon nitride composites”, Science and Engineering of Composite Materials, vol. 25, no. 2, pp. 261-271, 2018.

2018

C. Magaacibhi Athev, J. Nithin Alistar, and Dr. Radhika N, “Synthesis of Al LM25/TiC Composite Using Squeeze Casting Method and Investigation of its Mechanical and Adhesive Wear properties”, Materials Today: Proceedings, vol. 5, no. 5, Part 2, pp. 12681 - 12692, 2018.[Abstract]


LM25 reinforced with 10 wt.% Titanium Carbide was fabricated using squeeze casting technique and a cylindrical specimen with dimensions of 50 mm diameter and 150 mm length was obtained. The cast composite specimen was subjected to hardness and tensile test using Vicker’s hardness tester and Universal Testing Machine respectively. The hardness and tensile test results revealed 129 HV and 143 MPa respectively. Microstructural analysis was done and uniform distribution of reinforcement particles was observed in the matrix. Dry sliding wear experiments were conducted using pin-on-disc tribometer based on Taguchi’s L27 orthogonal array by varying process parameters such as load (15, 25, 35N), sliding distance (750,1250,1750m) and sliding velocity (1.5m/s, 2.5m/s, 3.5m/s). Signal-to-Noise ratio and Analysis of Variance were used to find out the most influential process parameter. The results revealed that the wear rate increases as applied load increases and it decreases as sliding velocity and sliding distance increases. Load was found to be the most dominating parameter (54.2%) followed by sliding velocity (8.5%) and sliding distance (2.6%). Interaction between wear parameters also had a significant effect on wear rate. Regression model was developed and validated with confirmation experiments with minimum error. Worn surfaces were examined using Scanning Electron Microscope and severe delamination was observed at maximum load.

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2018

S Ram Kumar, S Gowtham, and Dr. Radhika N, “Fabrication of Cu-Sn/SiC Metal Matrix Composites and Investigation of its Mechanical and Dry Sliding Wear Properties”, Materials Today: Proceedings, vol. 5, no. 5, Part 2, pp. 12757-12771, 2018.[Abstract]


Requisite for advanced materials with high hardness, high tensile strength and improved wear properties has been drastically increased in recent times. The main objective of this paper is to fabricate unreinforced copper alloy and Cu-Sn/SiC composite with varying wt% of SiC (5, 10, and 15) by liquid metallurgy route and to investigate its microstructure, mechanical properties and dry sliding wear behavior. The hardness and tensile strength of alloy and composites are measured on Vickers micro hardness tester and Universal Testing Machine respectively. Tensile test specimens are further subjected to fractography analysis and the results shows ductile mode of failure for alloy and mixed ductile and brittle mode failure for composites. Based on the test results, it is observed that Cu-Sn/10 wt% of SiC have uniform distribution of particles with optimum mechanical properties. Hence only these 10 wt% SiC composite is considered for dry sliding wear analysis and experiments are conducted using Pin-on-disc tribometer. Analysis of process parameters in three levels such as applied load (15,25,35 N), sliding distance (750,1250,1750 m) and sliding velocity (1,2 and 3 m/s) is done by Taguchi’s Design of Experiments technique based on L₂₇ orthogonal array. From Signal-to-Noise ratio and Analysis of Variance approach, the rank of process parameters as well as its influence on the response is found. The results reveal that the wear rate increases as applied load and sliding distance increases and the wear rate decreases as sliding velocity increases. The load is found to have the highest influence on wear rate (38.5%) followed by sliding distance (7%) and sliding velocity (7%). Interaction between the process parameters also contributed towards wear rate. The worn surfaces were examined using Scanning Electron Microscopy and observed the formation of mechanically mixed layer at high velocity condition. Thus, the fabricated composites can be used in applications like bearings and bushes to improve the wear resistance.

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2018

Dr. Radhika N, Manu Sam, B. Ashish Guhan, and Kiran Aravidha, “Enhancement of Tribological Properties of Al 6060 by Spray Coated TiO2 Nanoparticle”, Transactions of the Indian Institute of Metals, vol. 71, no. 8, pp. 1859–1870, 2018.[Abstract]


Al 6060 alloy was coated with TiO2 by spray pyrolysis technique at 400 °C using Titanium isopropoxide as precursor. The adhesion of the coating with the alloy was enhanced by annealing at 450 °C for 1 h which increased the hardness by 50{%}. Dry sliding wear resistance was experimented based on Taguchi's L27 array using pin-on-disc tribometer by varying parameters such as applied load (15, 25 and 35 N), sliding distance (500, 1000 and 1500 m) and sliding velocity (1.5, 2.5 and 3.5 m/s). Analysis of Variance predicted the major influence by load, followed by velocity and distance. Trend depicted an increase in wear rate with load and distance, whereas with velocity it decreased initially and then increased. Optimum condition for maximum wear resistance was determined from the Signal-to-Noise ratio. Experimental results were validated using regression equation with an error less than 3{%}. Scanning Electron Microscope analysis of the worn surfaces had revealed more defoilage and lay-off as the applied load was increased.

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2018

Dr. Radhika N, “Analysis of three body abrasive wear behavior of centrifugally cast aluminium composite reinforced with Ni coated SiC using Taguchi technique”, Tribology in Industry, vol. 40, no. 1, pp. 81-91(11), 2018.[Abstract]


The aim of the present research is to determine the abrasive wear behavior of functionally graded Al LM21/10wt.% Ni coated SiC composite fabricated by centrifugal casting route. The centrifugal cast hollow cylindrical part has the dimensions of Øout150 mm x Øin135 mm x 160 mm. Ni was coated over SiC reinforcement particles by electroless coating process and the presence of Ni content on reinforcement particles were confirmed by Energy Dispersive Spectroscopy analysis (EDS). Abrasive wear test was conducted as per Taguchi’s L27 orthogonal array design. The parameters selected for wear experiments were: load (29, 34 and 41 N), rotational speed (100, 150 and 200 rpm) and radial distance (1, 6 and 11 mm) from outer periphery. The wear characteristics of the composite were analyzed using signal-to-noise and analysis of variance. Results showed that the radial distance had major impact on the wear rate (40.59 %), followed by the applied load (29.7 %) and rotational speed (14.85 %). The regression equation was developed and validated with confirmatory experiments and the error was found to be less than 10 %. Scanning Electron Microscope (SEM) analysis was done on the worn specimens and observed lesser wear rate at the radial distance of 1 mm.

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2018

Dr. Radhika N, “Comparison of the mechanical and wear behaviour of aluminium alloy with homogeneous and functionally graded silicon nitride composites”, Science and Engineering of Composite Materials, vol. 25, no. 2, pp. 261-271, 2018.[Abstract]


Homogeneous and functionally graded LM25 aluminium (Al) composites were fabricated by incorporating silicon nitride (10 wt%, 40 µm) particles through liquid metallurgy and centrifugal casting, respectively. The performance of these composites was compared with unreinforced alloy. The microstructural behaviour of the surfaces of unreinforced alloy, homogeneous composite and functionally graded composite (outer, middle and inner surfaces) were examined through optical microscopy. These surfaces were also evaluated for mechanical properties. An abrasive wear test was conducted on all these surfaces to determine their effect on wear rate. The microstructural results revealed a particle-rich region at the outer surface of the functionally graded composite material and uniform dispersion of reinforcement particles in the homogeneous composite. The outer region of the functionally graded composite showed greater hardness and the homogeneous composite displayed higher tensile strength. The abrasive wear rate increased with an increase in load and decreased with an increase in speed, and the particle-rich outer surface showed a lower wear rate. Scanning electron microscopy analysis revealed a particle-rich outer surface of functionally graded composite with fewer scratches. Therefore, higher wear resistance was observed at the outer periphery of functionally graded composites and this property can be well-utilised in automotive tribo-components such as in cylinder liners for improved performance.

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2018

Aravindh Venkatachalam, Palakollu Venkata Sai Anurag, Toppey Dhuruvan Sadanand, and Dr. Radhika N, “Optimization of the milling parameters for an Al/Si 3 N 4 functionally graded composite using grey relational analysis”, Materials Testing, vol. 60, no. 2, pp. 215-221, 2018.

2018

Manu Sam and Dr. Radhika N, “Effect of Heat Treatment on Mechanical and Tribological Properties of Centrifugally Cast Functionally Graded Cu/Al2O3 Composite”, Journal of Tribology, vol. 140, no. 2, pp. 1-7, 2018.[Abstract]


A functionally graded Cu–10Sn–5Ni metal matrix composite (MMC) reinforced with 10 wt % of Al2O3 particles was fabricated using the centrifugal casting process with dimension Φout100 × Φin85 × 100 mm. The mechanical and wear resistance of the composite has been enhanced through heat treatment. Samples from of the inner zone (9–15 mm) were considered for heat treatment, as this zone has higher concentration of less dense hard reinforcement particles. The samples were solutionized (620 °C/60 min) and water quenched followed by aging at different temperatures (400, 450, and 550 °C) and time (1–3 h). Optimum parametric combination (450 °C, 3 h) with maximum hardness (269 HV) was considered for further analysis. Dry sliding wear experiments were conducted based on Taguchi's L27 array using parameters such as applied loads (10, 20, and 30 N), sliding distances (500, 1000, and 1500 m), and sliding velocities (1, 2, and 3 m/s). Results revealed that the wear rate increased with load and distance whereas it decreased initially and then increased with velocity. Optimum condition for maximum wear resistance was determined using signal-to-noise (S/N) ratio. Analysis of variance (ANOVA) predicted the major influential parameter as load, followed by velocity and distance. Scanning electron microscope (SEM) analysis of worn surfaces predicted the wear mechanism, observing more delamination due to increase in contact patch when applied load increased. Results infer 8% increase in hardness after heat treatment, making it suitable for load bearing applications.

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2018

R. Anil Kumar and Dr. Radhika N, “Enhancement of mechanical and wear properties of tungsten carbide coated AA 6063 alloy using detonation gun technique”, Transactions of the IMF, vol. 96, no. 4, pp. 212-219, 2018.[Abstract]


Aluminium 6063 alloy as substrate was coated with WC-12% Co using the detonation spray gun technique. The coated specimen showed 5.6x increase in hardness over the uncoated substrate. Wear analysis was conducted on the coated specimen based on Taguchi’s L27 orthogonal by taking load (10, 20, 30 N), sliding velocity (1, 2, 3 m s−1) and sliding distance (750, 1250, 1750 m) as parameters. Wear rate was observed to increase with an increase in load and sliding velocity, whereas initial increase and a subsequent decrease in wear rate was observed with an increase in sliding distance. Analysis of variance predicted that load has a higher influence on the loss of material. Load and sliding distance interaction showed a high influence over loss of material than any other individual parameter’s influence. SEM and XRD analysis was conducted over worn surfaces to help elucidate the wear mechanism. The results from the present work may find application in piston rings and cylinder liners.

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2018

Dr. Radhika N and J. Andrew Jefferson, “Experimental Studies and Comparison of Centrifugally Cast Cu/SiC and Cu/Si3N4 Functionally Graded Composites on Mechanical and Wear Behavior”, Journal of Tribology, vol. 140, no. 6, p. 061602, 2018.[Abstract]


The objective of this research work is to synthesize functionally graded Cu-11Ni-4Si/10 wt % SiC, Cu-11Ni-4Si/10 wt % Si3N4 composite using horizontal centrifugal casting method and to analyze its mechanical and adhesive wear behavior. The cast samples with dimension of Øout100 × Øin70 × 100 mm were synthesized and variation in volume of SiC and Si3N4 particles on inner (1 mm), middle (8 mm), and outer surfaces (15 mm) along radial direction of the composites was analyzed. Microstructural images revealed that inner zone of the both composites had highest distribution of reinforcement particles. Tensile tests on inner (1–7 mm) and outer (8–15 mm) zones of composites revealed that the inner zones had highest tensile and yield strength. Fractography test was conducted for both composites at inner and outer zones to observe the mode of failure. Hardness tests taken along radial direction of the composites revealed that, the inner surface had better hardness and it reduced toward outer periphery. The outer and inner surfaces of Cu/SiC were compared with Cu/Si3N4 composites and results revealed that inner surface of Cu/SiC had highest wear resistance among all surfaces of composites. It was also observed that, while increasing load, wear rate increased with it for all composites. Wear rate of composites majorly decreased while increasing the sliding velocity due to formation of tribolayer. Scanning electron microscopy (SEM) analysis carried out on worn surfaces of Cu/SiC and Cu/Si3N4 composite revealed that, plastic deformation, and plowing were the dominant wear mechanism for varied parameters.

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2018

Dr. Radhika N, Punnath, N., and Katamreddy, S. Charan, “Multi-response optimisation of machining parameters in electrical discharge machining of Al LM25/AlB2 functionally graded composite using grey relation analysis”, International Journal of Machining and Machinability of Materials, vol. 20, no. 3, pp. 193-213, 2018.[Abstract]


The main objective of this paper is to optimise the tool wear rate, material removal rate and surface roughness in electrical discharge machining of aluminium diboride (AlB2) reinforced aluminium LM25 functionally graded composite. Peak current, pulse-on time and flushing pressure were the parameters considered for carrying out the experiments. The optimisation process was accomplished through grey relation analysis to obtain the minimum tool wear rate and surface roughness with maximum material removal rate. Analysis of variance was employed to determine the effect of each parameter on the responses. The results revealed that peak current, pulse-on time and flushing pressure had an impact of 43.45%, 19.45% and 12.94% respectively on the responses. The responses were also plotted against all combinations of parameters. The surface plots exposed that peak current played a major role in increasing material removal rate and surface roughness, while the increasing pulse-on time lead to a decrease in tool wear rate.

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2018

S. Sasidharan, Rahul Puthucode, Dr. Radhika N, and A. Shivashankar, “Investigation of three body abrasive wear behaviour of centrifugally cast Cu-Sn/SiC functionally graded composite using Design of Experiment Approach”, Materials Today: Proceedings, vol. 5, no. 5, Part 2, pp. 12657 - 12665, 2018.[Abstract]


Functionally graded metal matrix composite (Cu-10Sn/10 wt% SiC) was successfully fabricated by horizontal centrifugal casting method. The cast specimen of Ø100 x 100 x 20 mm was obtained. The centrifugal die rotates at 900 rpm and particle rich zone is obtained at inner periphery of cast sample due to the density difference between matrix and reinforcement. The specimen of dimension 75 x 25 x 12.5 mm was cut from the cast and abrasive wear test was carried out only at inner surface as per Taguchi’s Design of Experiment technique. L16 Orthogonal array was selected and experiments were carried out using three body dry abrasion tester by varying the process parameters such as load (25, 45, 64,89N), time (3, 5, 7, 9 mins) and speed (50,100,150,200 rpm) for four levels. Silica sand AFS 50/70 was used as an abrasive medium. The influence of these wear process parameters was analysed using Minitab software. Taguchi design provides analysis of experiments using Signal-to-Noise ratio and Analysis of Variance to find out the optimum level of parameters as well as its influence of each parameter on the response. The results revealed that, wear rate increases with increase in applied load and decreases and then increases as speed and time increases. Time was observed to be the most dominating factor (38.1%) followed by load (27.6%) and speed (22.8%). The worn surfaces were analyzed at varying parametric condition using Scanning Electron Microscope and found severe delamination with plouging as the major mechanism at high load condition.

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2018

Dr. Radhika N and Raghu, R., “Influence of process parameters on sliding wear of titanium nitride coated 6061 aluminium alloy”, Tribology in Industry, vol. 40, no. 2, pp. 203-212, 2018.[Abstract]


The objective was to study the wear behaviour of titanium nitride deposited onto 6061 aluminium alloy by DC magnetron sputtering technique. The coating on the aluminium substrate was characterized using optical microscopy, scanning electron microscopy and energy dispersive spectroscopy analysis. The hardness of the uncoated and coated aluminium specimens was tested using Vickers hardness tester and the results revealed that coated specimens had 26 % improvement compared to uncoated samples. The dry sliding wear behaviour of the titanium nitride coated aluminium specimens was investigated using pin on disc tribometer by response surface methodology. Five level central composite design was utilized and experiments were conducted by varying the wear process parameters such as load, velocity and sliding distance within the range 15 to 45 N, 1.5 to 4.5 m/s and 500 to 1500 m respectively. Wear test results revealed that increase in load increases the wear rate and increase in velocity and sliding distance decreases the wear rate. The developed model was validated through the comparison of experimental and model values which yields an error within 3 % confirms that the model was adequate. Scanning electron microscope was utilized to analyze the worn surfaces to study the wear mechanisms. © 2018 Published by Faculty of Engineering.

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2018

Nithin Raj and Dr. Radhika N, “Tribological Characteristics of LM13/Si3N4/Gr Hybrid Composite at Elevated Temperature”, Silicon, pp. 1-14, 2018.[Abstract]


LM13/12wt.%Si3N43wt.%Gr hybrid composite was fabricated by liquid metallurgy route and its tribological characteristics were tested using pin-on-disc tribometer. The experiments were conducted as per L27 orthogonal array to study the influence of process parameter at normal and elevated temperature (150 °C) by varying process parameters such as load (10, 20, 30 N), sliding velocity (1, 2, 3 m/s) and sliding distance (750, 1250, 1750 m). The results revealed that the wear rate at both temperatures was proportional to load due to the stress induced which fractures Si3N4 particles and stripes aluminium matrix. As the sliding velocity increases, wear rate showed an increasing trend due to three body abrasion from eroded Si3N4 grits. The wear rate was inversely proportional to sliding distance, because of MML (Mechanically mixed layer) formed from chemical reactions between tribo-layers. When load increases COF (Coefficient of friction) decreases then increases due to lubricating and tillage effect. As velocity and distance increases, COF decreases due to thermal softening, hardening of layer and also the lubrication effect produced by chemical reactions. Analysis of variance (ANOVA) and S/N ratio at room temperature and elevated temperature for both Wear rate and COF were developed to study the most significant parameters on corresponding responses. Confirmation experiments were conducted to validate multi-linear regression model. Worn surfaces were examined using scanning electron microscope (SEM) to investigate wear characteristics. Energy dispersive X-ray spectroscopy (EDAX) and X-ray diffraction (XRD) results confirmed the formation of MML and different phases formed during wear mechanism. The developed material can be used to fabricate cylinder liners, cylinder blocks and brake rotors. © 2018 Springer Science+Business Media B.V., part of Springer Nature

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2018

R. Jojith and Dr. Radhika N, “Fabrication of LM 25/WC functionally graded composite for automotive applications and investigation of its mechanical and wear properties”, Journal of the Brazilian Society of Mechanical Sciences and Engineering, vol. 40, no. 6, p. 292, 2018.[Abstract]


Functionally graded Al LM 25/10 wt{%} WC composite of dimension ∅out 100 × ∅in 60 × 100 mm was fabricated using centrifugal casting method. Mechanical and tribological properties of outer (1 mm), middle (11 mm) and inner (18 mm) layers from outer periphery of hollow cylindrical component were studied. Microstructural investigation revealed maximum distribution of reinforcements in outer layer, followed by middle and inner layer. Outer periphery had the highest hardness while outer zone displayed better tensile characteristics. Fractographs revealed brittle nature at outer layer due to high concentration of WC particles while a combined mode of ductile and brittle failure was observed at inner layer. Wear rate of outer layer increased linearly with increasing applied load, nonlinearly with increasing sliding velocity and sliding distance. Worn surface morphologies revealed fine and shallow grooves at outer layer ensuring mild material removal. Mild to severe wear transition was observed with increasing applied load. Mechanically mixed layer formation was observed with increasing velocity. This composite having enhanced mechanical and wear properties at outer zone is suitable for automotive applications such as pistons, liners, brake disks and bearings.

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2018

Dr. Radhika N, Karthik, R., Gowtham, S., and Ramkumar, S., “Synthesis of Cu-10Sn/SiC Metal Matrix Composites and Experimental Investigation of its Adhesive Wear Behaviour”, Silicon, pp. 1-10, 2018.[Abstract]


The objective is to fabricate Cu-10Sn alloy and its composites reinforced with varying wt% of SiC (5, 10 and 15) to investigate its dry sliding wear behaviour. Microstructural analysis for composites revealed well dispersed SiC particles within matrix except for 15 wt% SiC composite, where agglomeration took place. Amongst all composites and alloy, 10 wt% of SiC composite had better hardness (144 HV). The tribological analysis using Pin-on-Disc tribometer for all alloy and composites revealed increase in wear rate with increase in load and distance for all combinations of parameters (load, sliding distance, and sliding velocity). Worn surface analysis concluded that the wear rate decreased with increase in velocity for both 5 and 10 wt% SiC composite due to formation of Mechanically Mixed Layer. The composite with 10 wt% SiC showed enhanced wear resistance and hence can be used for tribological applications like bearings and bushes. © 2018 Springer Science+Business Media B.V., part of Springer Nature

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2018

Dr. Radhika N, Teja, K., Rahul, K., and A, S., “Fabrication of Cu-Sn-Ni /SiC FGM for Automotive Applications: Investigation of its Mechanical and Tribological Properties”, Silicon, vol. 10, no. 4, pp. 1705–1716, 2018.[Abstract]


The objective of this research is to fabricate a functionally graded Cu/SiC composite (Øout100 × Øin85 × 100 mm) using a horizontal centrifugal casting technique and to examine its mechanical and dry sliding wear characteristics. Microstructure of the composite was observed at outer (1 mm), middle (8 mm) and inner (14 mm) regions using a metallurgical microscope and results showed that the inner region had a high concentration (35{%}) of reinforcement particles compared to the other two regions. Mechanical properties were tested along the radial direction of the composite and results showed that maximum tensile strength and hardness were found to be 341 MPa and 280 HV respectively, at the inner region of the composite. Fractograpy examination revealed that the outer and inner regions were fractured by ductile and brittle modes of failures, respectively. The dry sliding wear tests were performed only at the inner region of the composite with selected parameters of load (10–30 N), sliding distance (500–1500 m) and sliding velocity (1–3 m/s) using a pin-on-disc tribometer. Analysis of variance and signal-to-noise ratio were used to study the effects of parameters on the wear rate of the composite and it was found that the load (54{%}) had highest influence followed by sliding distance (18.2{%}) and sliding velocity (3.7{%}). Worn surfaces were observed by a scanning electron microscope and it was confirmed that mild wear, severe plastic deformation, ploughing, delamination and wear debris were important wear mechanisms at different sliding conditions. Hence, this composite is suggested for use in bearings and bushes application, where the wear resistance is a primary consideration.

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2018

Manu Sam and Dr. Radhika N, “Development of functionally graded Cu–Sn–Ni/Al2O3 composite for bearing applications and investigation of its mechanical and wear behavior”, Particulate Science and Technology, pp. 1-12, 2018.[Abstract]


This study investigates the mechanical and tribological properties of a functionally graded Cu–Sn–Ni/Al2O3 metal matrix composite, synthesized using horizontal centrifugal casting technique with dimension Φout100 × Φin85 × 100 mm. The microstructure was examined along radial distances at 1, 8, and 13 mm from outer periphery. Specimens were tested for tensile strength from outer (1–8 mm) and inner zone (9–15 mm) of the casting and fractured surfaces were subjected to fractographic analysis. Wear resistance of inner layer was experimented using pin-on-disc tribometer based on Taguchi’s L27 orthogonal array using three variable process parameters, such as applied loads (10, 20, and 30 N), sliding velocities (1, 2, and 3 m/s), and distances (500, 1000, and 1500 m). Optimum parameters were determined for wear rate on “smaller-the-better” basis using signal-to-noise ratio. Analysis of variance predicted the effect of each influential parameter and their interactions. Results depict that wear rate increased with load and distance, forming phases such as Cu3Sn, Ni3Sn, Cu6Sn5, etc. Worn surfaces analysis using scanning electron microscope predicted the formation of mechanically mixed layers, showing a V-trend influence of velocity on wear. Thus, fabricated composite shows the replaceability of conventional leaded bearing materials with superior copper functionally graded composites having better wear characteristics.

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2018

J. Chandra C, Dr. Radhika N, Khushal A. Bhatija, and Saalai Thenagan R, “Fabrication of light-weight Al LM13/TiS2 metal matrix composites and investigation of its wear characteristics”, Particulate Science and Technology, pp. 1-8, 2018.[Abstract]


This paper aims to study the dry sliding wear characteristics of LM13 aluminum alloy matrix containing titanium disulfide (TiS2) as the reinforcement (10 wt%, average size 37 µm) fabricated through liquid metallurgy route. Microstructural examination and Vickers hardness test were performed on the sample to investigate uniform distribution of the reinforcement particles in the composite. Energy Dispersive X-Ray Analysis and X-Ray Diffraction techniques were used to characterize the composite. The hardness test gave a result of 105.94 HV. The dry sliding wear experiments were designed by a five-level central composite design developed using response surface methodology. The factors considered were load, sliding distance, and velocity which were varied in the range of 10–30 N, 500–1500 m, and 1–3 m/s, respectively. The experiments were then performed at room temperature using a pin-on-disc tribometer for 20 combinations. The generated regression equation showed that the developed model established a proper relation between the process variables and the response. Load being the most influential factor showed increasing trends of wear rate in the surface plots against both velocity and sliding distance. The wear rate exhibited a nonlinear trend in the surface plots against sliding distance and velocity. Scanning electron microscopy results showed greater wear at higher loads due to higher surface damage. Thus, the fabricated Al/TiS2 composite with the optimum wear process parameters can be well utilized for application where wear becomes a major consideration.

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2018

R. Jojith and Dr. Radhika N, “Mechanical and tribological properties of LM13/TiO2/MoS2 hybrid metal matrix composite synthesized by stir casting”, Particulate Science and Technology, pp. 1-13, 2018.[Abstract]


This paper involves the fabrication of LM13/TiO2 (12 wt%)/MoS2 (3 wt%) hybrid metal matrix composite and unreinforced alloy using liquid metallurgy route and evaluation of mechanical properties and adhesive wear characteristics. Microstructural investigation revealed homogeneous distribution of reinforcements in matrix. Hardness and tensile properties revealed that the composite had attained an improvement of 16.5 and 35%, respectively, over alloy. Wear characteristics were analyzed using pin-on-disk tribometer by varying load (10–40 N), sliding velocity (1–4 m/s), and sliding distance (500–2000 m). Statistical analysis was performed using response surface methodology to obtain the optimum wear process parameters for achieving maximum wear resistance. Results revealed that, with increasing load and sliding velocity, an increment in wear rate was observed for both alloy and composite, while a decline was observed with increasing sliding distance for composite and vice versa for alloy. Worn surface analysis revealed that load plays a prominent role in deciding wear rate, followed by sliding velocity. Sliding distance had less effect on wear rate of composite while it had significance on alloy. This hybrid composite can replace the conventional material used in automotive applications involving tribological importance. © 2018 Taylor & Francis

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2018

Dr. Radhika N, R. Ramprasad, and S. Nivethan, “Experimental Investigation on Adhesive Wear Behavior of Al–Si6Cu/Ni Coated SiC Composite Under Unlubricated Condition”, Transactions of the Indian Institute of Metals, vol. 71, no. 5, pp. 1073–1082, 2018.[Abstract]


This paper studies the dry sliding wear behavior of Al–Si6Cu/Ni coated SiC metal matrix composite fabricated using stir casting technique. The SiC reinforcement particles coated with Ni by electroless coating were incorporated at 10-wt% into the metal matrix. The wear behavior was studied on unlubricated pin-on-disc tribometer based on design of experiments modelled using Response Surface Methodology for various sliding parameters such as applied load, sliding velocity and sliding distance. The minimum wear rate condition and optimum condition of the parameters were detected from the developed model. The analysis of variance showed the influence of each parameter on wear rate. The confirmation experiments were done to ensure the validity of the developed regression model. The worn-out surface morphologies of the metal composite were studied using scanning electron microscope analysis. From the experimental results it was found that the parameter which influenced the wear behavior was applied load followed by sliding velocity and distance. The confirmatory experiments confirmed the RSM’s design as precise statistical model in developing regression results with less error. The surface plot of wear characteristics showed that irrespective of the conditions of sliding velocity and distance the wear rate increased on increasing the load. The wear rate exhibited a non linear relationship with sliding velocity and distance. The scanning electron microscopy revealed that higher material deformation was observed at higher load resulting in severe wear of the composite material. © 2017 The Indian Institute of Metals - IIM

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2018

Dr. Radhika N, Dr. Thirumalini S., and Shivashankar, A., “Investigation on Mechanical and Adhesive Wear Behavior of Centrifugally Cast Functionally Graded Copper/SiC Metal Matrix Composite”, Transactions of the Indian Institute of Metals, vol. 71, no. 6, pp. 1311-1322, 2018.[Abstract]


The objective of this work is to fabricate functionally graded unreinforced copper alloy (Cu–10Sn) and a Cu–10Sn/SiC composite (Øout100 × Øin70 × 100 mm) by horizontal centrifugal casting process and to investigate its mechanical and tribological properties. The microstructure and hardness was analysed along the radial direction of the castings; tensile test was conducted at both inner and outer zones. Microstructural evaluation of composite indicated that the reinforcement particles formed a gradient structure across the radial direction and maximum reinforcement concentration was found at the inner periphery. Hence maximum hardness (205 HV) was observed at this surface. Tensile test results showed that, the tensile strength at inner zone of composite was observed to be higher (248 MPa) compared to that of the outer zone and unreinforced alloy. As mechanical properties showed better results at inner periphery, dry sliding wear experiments were carried out on the inner periphery of composite using pin-on-disc tribometer. Process parameters such as load (10–30 N), sliding distance (500–1500 m) and sliding velocity (1–3 m/s) were analyzed by Taguchi L27 orthogonal array. The influence of parameters on wear rate was analyzed by signal-to-noise ratio and analysis of variance. Analysis results revealed that load (54{%}) had the highest effect on wear rate followed by sliding distance (18.2{%}) and sliding velocity (3.7{%}). The wear rate of composite increased with load and sliding distance, but decreased with sliding velocity. Regression equation was developed and was validated by confirmatory experiment. Worn surface of composite was observed using scanning electron microscopy and transition of wear was observed at all extreme conditions.

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2018

Dr. Radhika N and Raghu, R., “Effect of Centrifugal Speed in Abrasive Wear Behavior of Al-Si5Cu3/SiC Functionally Graded Composite Fabricated by Centrifugal Casting”, Transactions of the Indian Institute of Metals, vol. 71, no. 3, pp. 715–726, 2018.[Abstract]


Centrifugal casting was adopted for fabricating AlSi5Cu3/10 wt% SiC functionally graded metal matrix composite under three different centrifugal speeds of 800, 1000 and 1200 rpm, and hollow cylindrical components (φout 150 × φin 132 × 150 mm) were obtained. Microstructures of outer and inner periphery of all composites were observed through optical microscope and micro hardness of outer, intermediate and inner region of composite was tested using Vicker’s hardness tester. Results revealed that outer region of the composites centrifuged at all speeds have particle rich region with higher hardness. Abrasive wear experiments were conducted only on surface of particle rich region based on Taguchi’s technique by varying parameters such as centrifugal speed of casting process, rotating speed and applied load of abrasive wear tester. Analysis of variance results revealed that, centrifugal speed had highest significance on wear rate. Abraded surfaces were examined using scanning electron microscope and the maximum wear resistance was observed on particle rich zone of composite centrifuged at 1200 rpm. © 2017 The Indian Institute of Metals - IIM

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2018

Dr. Radhika N and Raghu, R., “Study on three-body abrasive wear behavior of functionally graded Al/TiB2 composite using response surface methodology”, Particulate Science and Technology : An International Journal, vol. 36, no. 7, pp. 816-823, 2018.[Abstract]


Functionally graded LM13 Al/10 wt% TiB2 metal matrix composite has successfully produced under centrifugal casting. Hollow cylindrical composite with dimensions 150 × 150 × 15 mm was produced under rotating centrifugal speed of 1100 rpm. Microstructural characteristics were studied on the composite surfaces at distance of 1, 5.5, and 10 mm from outer periphery of the casting, and the results revealed that surface at distance of 1 mm has presence of more reinforcement particles. An objective of this study was to characterize abrasion wear behavior at the composite surfaces using dry abrasion tester. Mathematical models were developed using response surface methodology to study the relationship of parameters such as load, speed, and distance from outer periphery with abrasion wear rate. Face centered Central Composite Design with 20 experiments was preferred for dry abrasion test. Adequacy of model was predicted through analysis of variance, and the significance test result shows that load has major impact on the wear rate. The optimized parametric condition to obtain minimum wear rate was found as load of 33 N, speed of 112 rpm, and distance of 1 mm from outer periphery. Scanning electron microscopy analysis done at worn out surface showed maximum wear resistance at the outer periphery. © 2017 Taylor & Francis.

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2018

Dr. Radhika N and Raghu, R., “Prediction of mechanical properties and modeling on sliding wear behavior of LM25/TiC composite using response surface methodology”, Particulate Science and Technology: An International Journal, vol. 36, no. 1, pp. 104-111, 2018.[Abstract]


Aluminum LM25/TiC (10 wt%) metal matrix composite was developed using the liquid metallurgy route. The microstructural examination and the mechanical properties such as hardness and tensile strength were investigated on the composite specimens. The tribological behavior of the composite was studied using central composite design (CCD) based on response surface methodology (RSM) under the influence of wear process parameters such as applied load, sliding velocity and sliding distance. Pin-on-disc tribometer was utilized for conducting the experimental runs and the model was constructed based on the obtained wear rates. Confirmation experiments and analysis of variance were performed to ensure the adequacy of the constructed model. Microstructural examination reveals that uniform dispersion was attained in the composite, which enhances the hardness and the tensile strength. The wear results showed that the wear rate increased with increase in load, decreases with increase in velocity and varies nonlinearly with sliding distance. Scanning electron microscopic (SEM) analysis was performed to examine the worn surface morphologies and the worn surfaces revealed that TiC reinforcement protects the matrix from more material removal at all conditions. The developed composite can be utilized for the tribological applications like engine block, cylinder liners and pistons.

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2017

Nithin Raj and Dr. Radhika N, “Optimisation of WEDM process parameters during machining of Cu-Ni-Si/TiC FGM using Taguchi's method”, International Journal of Materials Engineering Innovation, vol. 8, no. 3-4, pp. 282-295, 2017.[Abstract]


Functionally graded Cu11Ni4Si/10wt%TiC composite is fabricated using centrifugal casting and machined using wire-electrical discharge machine. The research objective is to find the optimal process parameter during machining and to study its influence on material removal rate (MRR) and surface roughness (Ra). The experiments were conducted on L9 orthogonal array by varying process parameters such as pulse on time (TON-115,120,125 µs), peak current (IP-100, 150, 200A) and wire feed rate (WF-2, 3, 4 mm/min). The trend of TON for MRR increased initially and then decreased, whereas for Ra, the trend is increasing. The relationship of IP and MRR initially decreased and then increased, whereas for Ra decreased steadily. The trend for WF was found to be linearly increasing for both MRR and Ra. Analysis of variance and S/N ratio revealed that the WF(98.19%) was the most significant parameter influencing MRR followed by TON and IP. TON(74.63%) was the most significant parameter influencing Ra followed by IP and WF.

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2017

A. Mohandas and Dr. Radhika N, “Studies on Mechanical Behaviour of Aluminium/Nickel Coated Silicon Carbide Reinforced Functionally Graded Composite”, Tribology in Industry, vol. 39, no. 2, pp. 145-151, 2017.[Abstract]


The aim of the work is to fabricate functionally graded aluminium (AlSi6Cu)/ nickel coated SiC metal matrix composite using centrifugal casting route. SiC particles (53-80 µm) were coated with nickel using electroless coating technique to enhance the wettability with aluminium matrix. Several attempts were made to coat nickel on SiC by varying the process temperature (65 °C, 75 °C, and 85 °C) to obtain a uniform coating. Silicon particles coated with nickel were characterised using EDS enabled Field Emission Scanning Electron Microscope and it was found that the maximum nickel coating on SiC occurred at a process temperature of 75°C. This nickel coated SiC particles were used as the reinforcement for the manufacture of functionally graded metal matrix composite and a cast specimen of dimensions 150×90×15 mm was obtained. To ensure the graded properties in the fabricated composites, microstructure (at a distance of 1, 7 and 14 mm) and hardness (at a distance of 1, 3, 7, 10 and 14 mm) from outer periphery taken in the radial direction was analysed using Zeiss Axiovert metallurgical microscope and Vickers micro hardness tester respectively. The microstructure reveals presence of more SiC particles at the outer periphery compared to inner periphery and the hardness test shows that the hardness also decreased from outer periphery (90 HV) to inner periphery (78 HV).Tensile strength of specimen from outer zone (1-7mm) and inner zone (8-14 mm) of casting was also tested and found out a value of 153.3 Mpa and 123.3 Mpa for the outer zone and inner zone respectively. An important observation made was that the outer periphery of casting was particle rich and the inner periphery was particle deficient because of centrifugal force and variation in density between aluminium matrix and reinforcement. Functionally graded Al/SiC metal matrix composite could be extensively used in automotive industry especially in the manufacture of liners and brake drums

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2017

Dr. Radhika N, M. Praveen, and Swarnava Mukherjee, “Influence of process parameters on three body abrasive wear behaviour of functionally graded Aluminium alloy reinforced with alumina”, Journal of Engineering Science and Technology, vol. 12, no. 11, pp. 2866-2879, 2017.[Abstract]


The aim of this research is to fabricate functionally graded aluminium composite reinforced with 15 wt% alumina using centrifugal casting technique with dimensions of Øout160 x Øin145 x 150 mm and to investigate its three-body abrasive wear behavior. Hardness tests and microstructural examinations were performed at distances of 2, 8 and 14 mm from outer diameter. Based on hardness test results, wear tests were carried out at a distance of 2 mm from outer diameter and a total of 16 experiments were conducted as per Taguchi’s Design of Experiments. The parameters varied were load applied on the specimen (29, 34, 41 and 53 N), sliding speed at the surface of the specimen (75, 100, 125 and 150 rpm) and time of operation (3, 5, 7 and 9 mins) and their influence on the wear rate was analyzed using Analysis of Variance and Signal-to-Noise ratio. The most dominating parameter was found out to be the load applied and subsequently a regression equation was generated. Finally, the worn surfaces were analyzed using Scanning Electron Microscope. The images obtained were used to explain the wear mechanisms and it was found out that increased load caused severe ploughing action on the surface. This indicates that the load applied on the component fabricated with this material is the major factor in determining is life. © School of Engineering, Taylor’s University.

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2017

Dr. Radhika N and Raghu, R., “Characterization of mechanical properties and three-body abrasive wear of functionally graded aluminum LM25/titanium carbide metal matrix composite”, Materials Science and Engineering Technology, vol. 48, no. 9, pp. 882-892, 2017.[Abstract]


Several engineering components require location specific performance under operating conditions. A compositional/microstructural gradient can provide the performance required at specific locations and these materials were named as functionally graded materials. Functionally graded aluminium metal matrix composites were generally established for the tribo-components where high wear resistance was a necessity. Reports on three body abrasive wear behaviour of functionally graded materials was limited to date. In the present work, a new functionally graded system comprising aluminium/titanium carbide (10 wt%) was produced through stir casting route followed by centrifugal casting technique and its three body abrasive wear behaviour was investigated. Hollow cylindrical part with the dimensions of length 150 mm, outer diameter 150 mm and thickness 16 mm was obtained. Microstructural study was performed on outer (1 mm) and inner surface (13 mm) to analyze the compositional gradient across the thickness of the functionally graded composite. Hardness was measured on different surfaces along the radial distance from outer periphery and tensile test was conducted on the outer and inner zone. Abrasive wear test was conducted on different surfaces of the functionally graded composite under various loads and speeds at constant time. The microstructural results revealed that particle segregation was more at the outer surface and less at the inner surface. Wear test results showed that increase in wear rate was obtained with increase of load and decrease in wear rate was obtained with increase of speed. The outer surfaces of the functionally graded composite had greater mechanical properties and better wear resistance compared to other surfaces. Scanning electron microscopy analysis was done on the abraded surfaces and observed wear mechanisms were interpreted.

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2017

K. Sanesh, S. Shiam Sunder, and Dr. Radhika N, “Effect of reinforcement content on the adhesive wear behavior of Cu10Sn5Ni/Si3N4 composites produced by stir casting”, International Journal of Minerals, Metallurgy and Materials, vol. 24, no. 9, pp. 1052-1060, 2017.[Abstract]


The main objective of this paper was to fabricate Cu10Sn5Ni alloy and its composites reinforced with various contents of Si3N4 particles (5wt%, 10wt%, and 15wt%) and to investigate their dry sliding wear behavior using a pin-on-disk tribometer. Microstructural examinations of the specimens revealed a uniform dispersion of Si3N4 particles in the copper matrix. Wear experiments were performed for all combinations of parameters, such as load (10, 20, and 30 N), sliding distance (500, 1000, and 1500 m), and sliding velocity (1, 2, and 3 m/s), for the alloy and the composites. The results revealed that wear rate increased with increasing load and increasing sliding distance, whereas the wear rate decreased and then increased with increasing sliding velocity. The primary wear mechanism encountered at low loads was mild adhesive wear, whereas that at high loads was severe delamination wear. An oxide layer was formed at low velocities, whereas a combination of shear and plastic deformation occurred at high velocities. The mechanism at short sliding distances was ploughing action of Si3N4 particles, which act as protrusions; by contrast, at long sliding distances, direct metal–metal contact occurred. Among the investigated samples, the Cu/10wt% Si3N4 composite exhibited the best wear resistance at a load of 10 N, a velocity of 2 m/s, and a sliding distance of 500 m. © 2017, University of Science and Technology Beijing and Springer-Verlag GmbH Germany. More »»

2017

R. Nithesh, Dr. Radhika N, and S. Shiam Sunder, “Mechanical Properties and Adhesive Scuffing Wear Behavior of Stir Cast Cu-Sn-Ni/Si3N4 Composites”, ASME Journal of Tribology, vol. 139, no. 6, pp. 1-9, 2017.[Abstract]


The modern technology developments have seeded for the necessity of composite materials that are incorporated with high hardness, high tensile strength, and better wear properties. Cu-Sn-Ni alloy as well as the composites of varying weight percentage of Si3N4 (5, 10, and 15) are fabricated by liquid metallurgy technique. The alloy and composites are tested for their tensile strength and hardness on Universal Testing Machine and Vickers microhardness tester, respectively. Based on the tests, Cu-Sn-Ni/10 wt. % of Si3N4 is found to have optimum mechanical properties. The scuff type adhesive wear behavior is studied through pin-on-disk tribometer under dry sliding conditions for Cu-Sn-Ni/10 wt. % of Si3N4 composite. Taguchi's design of experiments technique based on L27 orthogonal array model is used for analyses of process parameters in three levels such as applied load (10, 20, and 30 N), sliding distance (500, 1000, and 1500 m), and sliding velocity (1, 2, and 3 m/s). The parameters are ranked based on the signal-to-noise ratio and the analysis of variance approach. Based on wear results, applied load is found to have highest stature on influencing wear rate followed by sliding distance and sliding velocity. A generalized wear rate equation is obtained based on the linear regression model and its feasibility is checked. Scanning electron microscope (SEM) analyses revealed severe delamination occurred on maximum load condition. The development of this copper composite can have the possibility of replacing aluminum bearings.

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2017

Dr. Radhika N and M.L. Venkata Priyanka, “Investigation of adhesive wear behaviour of zirconia reinforced aluminium metal matrix composite”, Journal of Engineering Science and Technology, vol. 12, no. 6, pp. 1685-1696, 2017.[Abstract]


Aluminium alloy reinforced with zirconia (10 wt%) was fabricated using stir casting technique and specimens with diameter 20 mm and 100 mm length were obtained. The adhesive wear test was done on the fabricated specimens using a pin-on-disc tribometer. Taguchi’s method was used for designing the number of experiments and L27 orthogonal array was developed for analysis of wear rate. Optimisation of parameters like applied load (15 N, 25 N, 35 N), sliding distance (500 m, 1250 m, 2000 m) and sliding velocity (1.5 m/s, 2.5 m/s, 3.5 m/s) was done using Signal-to-Noise ratio analysis and Analysis of Variance. “Smaller the better” criteria was considered as objective model to analyse the wear resistance of the composite. Results revealed that applied load (73.83%) has major influence on wear behaviour followed by sliding distance (10.08%) and sliding velocity (8.25%). Scanning Electron Microscope analysis was done on the worn surfaces of the composite specimens and severe delamination was observed at high load condition. © School of Engineering, Taylor’s University.

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2017

Dr. Radhika N and Raghu Raman, “Investigation on Mechanical Properties and Analysis of Dry Sliding Wear Behavior of Al LM13/AlN Metal Matrix Composite Based on Taguchi's Technique”, ASME Journal of Tribology, vol. 139, no. 4, pp. 1-10, 2017.[Abstract]


LM13/AlN (10 wt. %) metal matrix composites (MMC) and unreinforced aluminum alloy were produced under stir casting route. Microstructural characteristics were examined on the developed composite using optical microscope. The hardness and tensile test were carried out on both unreinforced aluminum alloy and composite using Vickers hardness tester and universal testing machine (UTM), respectively. Dry sliding wear behavior of the composite and unreinforced aluminum alloy was evaluated using pin-on-disk tribometer based on the design of experiments approach. Experimental parameters such as applied load (10, 20, and 30 N), velocity (1, 2, and 3 m/s), and sliding distance (500, 1000, and 1500 m) were varied for three levels. Signal-to-noise (S/N) ratio analysis, analysis of variance, and regression analysis were also performed. The characterization results showed that reinforcement particles were uniformly distributed in the composite. The hardness and tensile test revealed greater improvement of property in composite compared to that of unreinforced alloy. Wear plot showed that wear was increased with increase in load and decreased with increase in velocity and sliding distance. S/N ratio analysis and analysis of variance (ANOVA) indicated that load has greater significance over the wear rate followed by velocity and sliding distance. Regression analysis revealed greater adequacy with the constructed model in predicting the wear behavior of composite and unreinforced aluminum alloy. Scanning electron microscopy (SEM) analysis is evident that the transition of wear from mild to severe occurred on increase of the load in the composite. Copyright © 2017 by ASME.

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2017

K. A. Bhatija and Dr. Radhika N, “Studies on sliding wear characteristics of aluminium LM25/silicon dioxide functionally graded composite and optimisation of parameters using response surface methodology ”, Materials Science and Engineering Technology, vol. 48, no. 6, pp. 1-11, 2017.[Abstract]


This paper deals with the study of dry sliding wear of LM25/silicon dioxide (10 wt.%) functionally graded composite. The composite was fabricated using stir casting technique and the melt was poured into a horizontal centrifugal die rotating at 1200 min−1. After casting, the specimen (length 150 mm, external diameter 150 mm and internal diameter 130 mm) was subjected to microstructure and hardness tests at three different depths from the outer periphery (1 mm, 8 mm and 13 mm). The results of the respective tests revealed that the outer periphery of the specimen had higher particle concentration and hardness. Then, wear test was done on a pin-on-disc tribometer at room temperature with the experiments designed using response surface methodology and by taking specimens of size 8 x 8 x 15 mm such that the surface undergoing wear was at 1 mm from the outer periphery of the cast. The process variables of load (10 - 40 N), velocity (1 - 4 m/s) and sliding distance (400 - 1200 m) were varied using a level 5 design and experiments were carried on for 20 different optimal combinations. From the regression equation generated for the wear response, it was found that load had maximum effect on the wear rate. The confirmation experiments proved that the regression model could serve well in predicting the wear rate for the given ranges of the continuous factors, for the given composite. Surface plots showed that the wear rate had an increasing trend with respect to load, which was the dominating continuous factor. Though the wear rate increased, severe delamination of the functionally graded composite was delayed. The optimum levels of the continuous factors to minimize the wear rate were found using response optimisation and found to be 10 N, 1.7576 m/s and 2000 m respectively. Scanning electron microscopy analysis of the worn surface of the specimens connected to the obtained trends and thus further validated the model developed. Thus, a functionally graded LM13 composite with silicon dioxid reinforcements is developed and a wear model to predict its wear rate under different process parameters is proposed with predictions of optimal performance conditions. This composite can increase life of components of wear applications in aerospace and automobile industry. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

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2017

Dr. Radhika N, “Fabrication of LM25/SiO2metal matrix composite and optimization of wear process parameters using design of experiment”, Tribology in Industry, vol. 39, no. 1, pp. 1-8, 2017.[Abstract]


LM25 aluminium alloy reinforced with 15 wt% SiO2 metal matrix composite was fabricated by liquid metallurgy technique. Microstructure of the fabricated composite specimen was observed using inverted metallurgical microscope and result showed uniform distribution of reinforcement particles in the matrix. The dry sliding wear behaviour of LM25/SiO2 composite was analyzed by conducting experiments using pin-on-disc tribometer. Taguchi’s method was used for designing the number of experiments and L16 orthogonal array was developed for wear analysis. Optimization of parameters like applied load (10 N, 20 N, 30 N, 40 N), sliding velocity (0.5 m/s, 1 m/s, 1.5 m/s, 2 m/s) and sliding distance (500 m, 1000 m, 1500 m, 2000 m) was done using Signal-to-Noise ratio analysis and Analysis of Variance. ‘smaller-the-better’ characteristic was chosen to analyze the dry sliding wear behaviour. Results found that load (69.17 %) had the highest impact on wear rate followed by sliding velocity (18.04 %) and sliding distance (1.5 %). The regression equation was developed and it was validated with confirmatory experiment. Scanning Electron Microscope analysis was done to observe the mechanism of the worn out composite specimen and found more delamination at the load of 40 N. © 2017 Published by Faculty of Engineering.

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2017

Dr. Radhika N and K. Sai Charan, “Experimental Analysis on Three Body Abrasive Wear Behaviour of Stir Cast Al LM 25/TiC Metal Matrix Composite”, Transactions of the Indian Institute of Metals, vol. 70, no. 9, pp. 2233–2240, 2017.[Abstract]


In this paper, the abrasive wear behavior of Al LM 25/10 wt% TiC metal matrix composite has been studied experimentally. The composite specimens were fabricated using stir casting technique. Microstructural evaluation revealed uniform distribution of reinforcement particles throughout the matrix. Abrasive wear experiments were designed for different values of load, speed and time through response surface methodology and were performed using three body abrasion tester. Surface plots for wear rate against all combinations of parameters revealed that wear rate increased with increasing load and time, but decreased with increasing speed. The generated regression equation established proper relation between parameters and wear rate, confirming the accuracy of the developed model. The results of optimization of process parameters revealed that a minimum wear rate of 0.00104 mm3/Nm was obtained at 27 N, 139 rpm and 3 min. Scanning electron microscope analysis results substantiated that wear rate was comparatively more at higher loads. © 2017 The Indian Institute of Metals - IIM

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2017

Dr. Radhika N and .Raghu, R., “Synthesis of functionally graded aluminium composite and investigation on its abrasion wear behavior”, Journal of Engineering Science and Technology, vol. 12, no. 5, pp. 1386-1398, 2017.[Abstract]


Functionally graded aluminium (Al-Si5Cu3) metal matrix composite reinforced with 10 wt-percent of boron carbide particles having average size of 33 µm was synthesized through horizontal centrifugal casting method. The specimen of length 150 mm and outer diameter of 154 mm with the thickness of 20 mm was produced under the centrifuging speed of 1000 rpm. Composite specimens were prepared as per ASTM standards from the casting and subjected to microstructural evaluation, hardness testing and three body abrasion wear test. The microstructural observation was done on the surfaces at the distance of 1, 2.5, 10 and 15 mm from the outer periphery of the casting and the result shows that larger amount of particles observed at distance of 2.5 mm and very less particles observed at the distance of 15 mm. The hardness test was conducted on the different surfaces in the radial direction from the outer periphery and found decrease in hardness from 2.5 to 15 mm. The abrasion wear test was conducted using dry abrasion tester for various loads of 28, 40 and 52 N at different distances from the outer periphery of the casting and the results revealed that wear rate gradually increases when moving towards the inner periphery and also with the increasing load. Therefore higher wear resistance was observed at the outer periphery and the lower wear resistance was obtained at the inner periphery. This property makes them suitable for using in wear applications such as in cylinder liners.

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2017

D. .Bhuvanesh and Dr. Radhika N, “Experimental investigation on tribological characteristics of silicon nitride reinforced aluminium metal matrix composites”, Journal of Engineering Science and Technology, vol. 12, no. 5, pp. 1295-1306, 2017.[Abstract]


Aluminium alloy (LM25) reinforced with silicon nitride was fabricated by liquid metallurgy route. The fabricated composite was investigated for dry sliding wear behaviour by conducting experiments using pin-on-disc tribometer. Set of experiments were planned using Taguchi’s technique and data analysis was carried out using L27 orthogonal array. Analysis of Variance (ANOVA) technique was used to determine the significance of parameter with respect to wear rate. Signal-to-Noise ratio was employed to detect the most and least influential parameter as well as their level of influence. ‘Smaller the wear’ characteristic was chosen for the analysis of dry sliding wear. Results implied that, the load has the primary effect on the wear succeeded by the effect of sliding velocity and sliding distance. Scanning Electronic Microscopic studies were carried out on worn surfaces to understand the wear mechanism.Tribological results indicated that LM25 aluminium alloy could be better utilized as a material for piston, rotor and bearings for long life in low speed applications. More »»

2017

Dr. Radhika N and Raghu, R., “The mechanical properties and abrasive wear behavior of functionally graded aluminum/AlB2 composites produced by centrifugal casting”, Particulate Science and Technology, vol. 35, no. 5, pp. 575-582, 2017.[Abstract]


Functionally graded aluminum composites reinforced with different average sized (15, 44, and 74 µm) aluminum diboride (AlB2) particles (10 wt%) have been fabricated through centrifugal casting process. The outer, middle, and inner surfaces of all the functionally graded composites were tested for their microhardness using a Vicker's hardness tester. The outer and inner zones of all the composites were investigated for their tensile strength using a universal testing machine. The abrasive wear test was conducted using dry abrasion tester on the outer region of the composites based on Taguchi's design of experiments, under the influence of parameters such as load, speed, and reinforcement size. The analysis of variance was performed and determined that load has major significance on the wear rate followed by reinforcement size and speed. Scanning electron microscopy analysis was performed on the worn-out surfaces and it was observed that outer surface of coarser particle reinforced composite with lesser scratches and minimum loss of material.

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2017

Dr. Radhika N, “Mechanical Properties and Abrasive Wear Behaviour of Functionally Graded Al-Si12Cu/Al2O3 Metal Matrix Composite”, Transactions of the Indian Institute of Metals, vol. 70, no. 1, pp. 145-157, 2017.[Abstract]


Mechanical properties and abrasive wear behaviour of functionally graded Al-Si12Cu/Al2O3 metal matrix composite fabricated under centrifugal casting technique was investigated and compared with unreinforced aluminium alloy. Hollow cylindrical component with dimensions 150 × 150 × 16 mm was produced under the centrifuging speed of 1200 rpm by incorporating 10 wt% Al2O3 particles of size 30–50 µm. The distribution of the Al2O3 reinforcement particles at outer, middle and inner surfaces in matrix was examined through the microstructural analysis. Hardness and tensile strength of the aluminium alloy and functionally graded composite were tested through microhardness tester and universal testing machine respectively. Abrasive wear of aluminium alloy and functionally graded composite was tested through dry abrasion tester for various loads and speeds on outer, middle and inner surfaces of composite specimens. Scanning electron microscopy analysis was carried out on the fractured tensile specimens and worn out specimens. The results revealed that particles were segregated more on the outer periphery and less on the inner periphery. The mechanical properties and the abrasive wear resistance of the functionally graded material were found higher than the unreinforced alloy. The wear rate was found to increase with increase in load, speed and for the distance from the outer periphery of the casting. The worn out surfaces revealed more cutting and ploughing as a result of three body abrasion wear caused by silica sand particles. © 2016 The Indian Institute of Metals - IIM

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2016

K. P. Vetrivel, R. Subramanian, K. Somasundaravinoth, and Dr. Radhika N, “Tribological and Frictional Characteristics of Alsi7mgWc-Graphite Hybrid Composites ”, Asian Journal of Research in Social Sciences and Humanities, vol. 6, no. 9, pp. 212-220, 2016.[Abstract]


Al based metal matrix composites offer higher specific strength, light weight along with enhanced wear resistance and lower coefficient of friction. In the present investigation, aluminium alloy hybrid composites containing 3 weight % graphite( size less than one micron) and 3 % , 6 % and 9 wt % tungsten carbide powder(size less than one micron) were produced by stir casting. Addition of tungsten carbide (WC) increases strength and wear resistance of composites, while graphite (Gr) reduces the coefficient of friction, thus improving the overall tribological characteristics. Composite specimens were tested at loads of 10N, 15N and 20N with the sliding speeds of 1m/s, 1.5m/s and 2m/s to evaluate their wear behaviour. Co efficient of friction was also analysed. As the applied load increased, the coefficient of friction and wear rate of the composite increased. Coefficient of friction showed a decrease with increasing sliding speed and reinforcement content. Hardness of the composite increased with an increase in WC content.

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2016

Dr. Radhika N and Raghu, R., “Synthesis of functionally graded Al LM25/zirconia composite and its sliding wear characterization using response surface methodology”, Iranian Journal of Materials Science & Engineering, vol. 13, no. 4, pp. 41-52, 2016.[Abstract]


Functionally graded aluminium/zirconia metal matrix composite was fabricated using stir casting technique followed by horizontal centrifugal casting process and a hollow cylindrical functionally graded composite (150 x 150 x 16 mm) was obtained with centrifuging speed of 1200 rpm. The microstructural evaluation and hardness test was carried out on the outer and inner surface of the functionally graded composite at a distance of 1 and 13 mm from the outer periphery. In Response Surface Methodology, Central Composite Design was applied for designing the experiments and sliding wear test was conducted as per the design using a pin-on-disc tribometer for varying ranges of load, velocity and sliding distance. The model was constructed and its adequacy was checked with confirmation experiments and Analysis of Variance. The microstructural examination and hardness test revealed that the outer surface of FGM had higher hardness due to the presence of particle rich region and the inner surface had lesser hardness since it was a particle depleted region. The wear results showed that wear rate increased upon increase of load and decreased with increase in both velocity and sliding distance. Scanning Electron Microscopy analysis was done on the worn specimens to observe the wear mechanism. It was noted that wear transitioned from mild to severe on increase of load and the outer surface of FGM was found to have greater wear resistance at all conditions.

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2016

K. S. Arunagiri and Dr. Radhika N, “Studies on Adhesive Wear Characteristics of Heat Treated Aluminium LM25/AlB 2 Composites.”, Tribology in Industry, vol. 38, no. 3, pp. 277-285, 2016.[Abstract]


The main aim of this study was to determine the adhesive wear characteristics of heat treated LM 25/AlB2 metal matrix composites fabricated using liquid metallurgy route. The composite samples were solutionized at 525 °C and then water quenched. Aging was done at different temperatures (160 °C, 175 °C, 200 °C and 250 °C) for different aging time (4 hrs, 6 hrs, and 8 hrs). Brinell hardness tester was used to evaluate the hardness of all aged samples and maximum hardness (82 HRB) was observed in the sample aged for 6 hours at 250 °C. Those heat treated specimens were taken for further experimentation on wear characteristics. Pin-on-disc tribometer was used to analyse the dry sliding wear characteristics and the experiments were conducted based on Taguchi's L16 orthogonal array by varying the process parameters of load (10 N, 20 N, 30 N and 40 N), sliding distance (400 m, 800 m, 1200 m and 1600 m) and sliding velocity (1 m/s, 2 m/s, 3 m/s and 4 m/s) for four levels. The dependence of wear rate on various parameters was found out using ANOVA and S/N ratio. The experimental result shows that sliding velocity (56.6 %) influences more on wear rate followed by load (23.09 %) and sliding distance (6.02 %). The regression equation was developed and the confirmatory result shows less error. The worn surfaces were analysed using Scanning Electron Microscope and severe delamination at the sliding velocity of 1m/s was found. More »»

2016

Dr. Radhika N, “Comparison of the mechanical and wear behaviour of aluminium alloy with homogeneous and functionally graded silicon nitride composites”, Science and Engineering of Composite Materials, 2016.[Abstract]


Homogeneous and functionally graded LM25 aluminium (Al) composites were fabricated by incorporating silicon nitride (10 wt%, 40 µm) particles through liquid metallurgy and centrifugal casting, respectively. The performance of these composites was compared with unreinforced alloy. The microstructural behaviour of the surfaces of unreinforced alloy, homogeneous composite and functionally graded composite (outer, middle and inner surfaces) were examined through optical microscopy. These surfaces were also evaluated for mechanical properties. An abrasive wear test was conducted on all these surfaces to determine their effect on wear rate. The microstructural results revealed a particle-rich region at the outer surface of the functionally graded composite material and uniform dispersion of reinforcement particles in the homogeneous composite. The outer region of the functionally graded composite showed greater hardness and the homogeneous composite displayed higher tensile strength. The abrasive wear rate increased with an increase in load and decreased with an increase in speed, and the particle-rich outer surface showed a lower wear rate. Scanning electron microscopy analysis revealed a particle-rich outer surface of functionally graded composite with fewer scratches. Therefore, higher wear resistance was observed at the outer periphery of functionally graded composites and this property can be well-utilised in automotive tribo-components such as in cylinder liners for improved performance. More »»

2016

Dr. Radhika N and Raghu, R., “Abrasive wear behavior of monolithic alloy, homogeneous and functionally graded aluminum (LM25/AlN and LM25/SiO2) composites”, Particulate Science and Technology : An International Journal, pp. 1-11, 2016.[Abstract]


Functionally graded metal matrix composites (MMCs) and homogenous composites (Al/AlN and Al/SiO2-10 wt%) have been fabricated through centrifugal casting and liquid metallurgy route, respectively. The properties of these composites were compared with aluminum alloy. Microstructural characteristics and hardness were studied on the surfaces of functionally graded materials (FGMs), homogenous composites, and unreinforced aluminum alloy using an optical microscope and a Vickers micro hardness tester, respectively. Tensile test was carried out on the outer and inner sections of FGMs and specimens from homogenous composites and alloy utilizing universal testing machines (UTMs). Three-body abrasive wear test was conducted for different loads and speeds to study their effect on the surfaces of composites and alloy using dry abrasion tester. Microstructural and hardness results reveal that the outer surface of aluminum nitride (AlN)-reinforced FGM has a particle-enriched region with the highest hardness. Tensile strength was found higher in both homogenous composites compared to zones of their FGMs. Abrasion wear rate was found increased with increase in load and decreased with increase in speed. The outer surface of AlN-reinforced FGM has higher wear resistance followed by the outer surface of SiO2-reinforced FGM. Scanning Electron Microscopy (SEM) analysis was performed on worn-out surfaces and observed particle-enriched outer surface of Al/AlN FGM with less abrasion.

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2016

Dr. Radhika N, “Analysis of tribological behaviour of functionally graded LM13 aluminium/TiS2 composite using design of experiments”, Tribology in Industry, vol. 38, pp. 425-434, 2016.[Abstract]


Functionally graded LM13 aluminium/10wt% TiS2 composite was fabricated by centrifugal casting method and hollow cylindrical part has the dimension of 150x150x20 mm was obtained. The microstructural evaluation and vicker’s micro-hardness test was carried out on the surfaces at the distance of 1, 6, 12 and 18 mm from the outer surface of functionally graded composites. The microstructural investigation reveals that the TiS2 reinforcement particles concentrated more on the outer periphery and less at the inner periphery of the composite. The hardness of the composite surface increases at the particle rich region of outer periphery and decreases towards inner region. The dry sliding wear experiments were conducted on the composite specimens as per plan of Taguchi’s L16 orthogonal array design. The parameters considered were load, sliding velocity, sliding distance and distance from outer periphery of the composite, varied for four levels. Signal- to- Noise ratio and Analysis of Variance were carried out and the significance test revealed that distance from outer periphery had major impact (43.11%) followed by sliding distance (31.19%), load (16.59%), and sliding velocity (7.33%). Adequacy of model was predicted through regression equation and the error was found to be less than 8%. The scanning electron microscope analysis carried out for the worn-out surfaces showed maximum wear resistance of the functionally graded composite at outer periphery. © 2016 Published by Faculty of Engineering.

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2016

Dr. Radhika N and Raghu, R., “Effect of abrasive medium on wear behavior of Al/AlB2 functionally graded metal matrix composite”, Tribology Online, vol. 11, pp. 487-493, 2016.[Abstract]


Centrifugal casting process was applied for fabricating the functionally graded Aluminium/10% AlB2 composite under the centrifuging speed of 1200 rpm and hollow cylindrical (150 × 150 × 15 mm) component has been obtained. The outer, middle and inner surfaces of the FGM those were at the distance of 1 mm, 8 mm and 15 mm from the outer periphery were taken for three body abrasive wear test and the applied load was varied (33 N to 80 N) on these surfaces in the presence of silica sand and alumina as abrasive mediums. The wear test results showed that increase in load and increase in distance from the outer periphery of the FGM increases the wear rate. The surfaces of the FGM abraded with silica sand displays higher wear rate than the surfaces abraded through alumina. SEM analysis has been performed on the surfaces abraded by both medium and it was observed that severity of wear was less in the presence of alumina as abrasive medium during the abrasion test. More »»

2016

J. Dinesh, G Mohammad Ashraf, and Dr. Radhika N, “Fabrication and characterization of Al LM25/TiB2 in-situ composites”, ARPN Journal of Engineering and Applied Sciences , vol. 11, pp. 6001-6005, 2016.[Abstract]


The Al LM25/TiB2 (10 wt %) composite is fabricated using in-situ process by stir casting method. LM25 alloy is melted in a graphite crucible at 8000C using electric furnace in argon gas atmosphere and a mixture of K2TiF6 and KBF4 is added to the melt gradually through the hopper attached at the top of the furnace. The melt is stirred with the aid of mechanical stirrer which rotates at 200 rpm for 40 minutes intermittently. The reaction between K2TiF6 and KBF4 in those conditions results in the formation of TiB2. This melt is poured in the stainless steel mould which is preheated at 2000C and the obtained casting have dimension 100 mm length and 20 mm diameter. The composite specimens are then machined according to the specification requirement of the experiments. All the specimens are polished using emery sheets of grade 1/0 and 2/0 followed by velvet polisher. The specimen used for microstructure analysis is further etched with Keller's reagent. Spectroscopy of LM25 alloy is carried out to observe its elemental composition. X-ray diffraction is used to ensure the formation of TiB2 during casting process. Inverted metallurgical microscope and Vickers hardness tester are used to study the microstructure and micro hardness of the fabricated composite respectively. The X-ray diffraction results revealed the formation of TiB2 particles in the fabricated composite. Microstructure analysis revealed uniform distribution of TiB2 in the aluminum matrix and Micro hardness test shows an increase in hardness of the composite (91HV) as compared to the un reinforced alloy (82HV) by 10%. © 2006-2016 Asian Research Publishing Network (ARPN). All rights reserved.

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2016

Dr. Radhika N and Raghu, R., “Development of functionally graded aluminium composites using centrifugal casting and influence of reinforcements on mechanical and wear properties”, Transactions of Nonferrous Metals Society of China (English Edition), vol. 26, pp. 905-916, 2016.[Abstract]


Functionally graded Al/B4C, Al/SiC, Al/Al2O3 and Al/TiB2 composites with constant 12% (mass fraction) of reinforcement were fabricated by centrifugal casting and hollow cylindrical components were obtained. Microstructural characteristics were investigated at outer surface of all composites and segregation of reinforcement particles was observed. Graded property of the composites with different reinforcements was investigated through hardness and tensile measurements. Results revealed that the outer peripheries of all composites exhibit higher hardness except in Al/B4C composite and the outer zones of all composites show higher tensile strength. Abrasive wear test was conducted on the outer peripheries of all composites and Al/TiB2 composite exhibits less wear rate. © 2016 The Nonferrous Metals Society of China. More »»

2016

L. V. Priyanka Muddamsetty and Dr. Radhika N, “Effect of heat treatment on the wear behaviour of functionally graded LM13/B4C composite”, Tribology in Industry, vol. 38, pp. 108-114, 2016.[Abstract]


Aluminium alloy reinforced with boron carbide (10 wt.%) was fabricated using stir casting method followed by centrifugal casting and the cylindrical specimen with dimension 150 x 150 x 15 mm was obtained. The composite specimens were heat treated at various aging temperatures and aging time for property improvement. Solution treatment was done at 525 °C for 5 hrs. Taguchi’s method was used for designing the plan of experiments and L27 orthogonal array was formulated for the analysis of data. The wear test was conducted on the outer periphery of centrifugally cast Functionally Graded composites using pin-on-disc tribometer. Optimization of parameters such as applied load (10 N, 20 N, 30 N), agingtemperature (150 °C, 175 °C, 200 °C) and aging time (2 hrs, 6 hrs, 10 hrs) was done using Signal-to-Noise ratio. “Smaller-the-better” criterion was used for analyzing the results. Results ended up with a conclusion that aging time (92.19%) had major influence on tribological behavior followed by aging temperature (5.36%) and applied load (1.95%). Scanning Electron Microscope (SEM) analysis was performed to understand the wear mechanism in heat treated specimens. © 2016 Published by Faculty of Engineering. More »»

2015

Dr. Radhika N, Balaji, T. V., and Palaniappan, S., “Studies on mechanical properties and tribological behaviour of LM25/SiC/Al2O3 composites”, Journal of Engineering Science and Technology, vol. 10, pp. 134-144, 2015.[Abstract]


This paper involves the study of mechanical properties and wear characteristics of LM25/SiC/Al2O3 hybrid metal matrix composites. Composite specimens of reinforcements ranging from 0 to 30 wt-% were fabricated using liquid metallurgy route. Mechanical properties such as hardness and tensile strength were analysed for both unreinforced alloy and composite specimens. Wear characteristics of composite specimens were studied using Pin-on-disc tribometer. Wear experiments were conducted with load range of 10 N to 30 N and velocity range of 1 m/s to 3 m/s. The sliding distance was kept 1500 m for all wear experiment. Worn out surfaces of composites were analysed using Scanning Electron Microscope. From experiments it was found that, the mechanical properties and wear resistance increased as the weight percentage of reinforcement increased. © School of Engineering, Taylor’s University

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2015

Dr. Radhika N and Raghu, R., “Parametric Study Of Dry Sliding Wear Behaviour Of Functionally Graded Al Lm25/Si3n4 Composite By Response Surface Methodology”, ADVANCED COMPOSITES LETTERS, vol. 24, pp. 130–136, 2015.

2015

Dr. Radhika N, “Prediction of Tool Condition During Turning of aluminium/alumina/graphite Hybrid Metal Matrix Composites Using Machine Learning Approach”, Journal of Engineering Science and Technology, vol. 10, pp. 1310–1325, 2015.[Abstract]


Aluminium/alumina/graphite hybrid metal matrix composites manufactured using stir casting technique was subjected to machining studies to predict tool condition during machining. Fresh tool as well as tools with specific amount of wear deliberately created prior to machining experiments was used. Vibration signals were acquired using an accelerometer for each tool condition. These signals were then processed to extract statistical and histogram features to predict the tool condition during machining. Two classifiers namely, Random Forest and Classification and Regression Tree (CART) were used to classify the tool condition. Results showed that histogram features with Random Forest classifier yielded maximum efficiency in predicting the tool condition. This machine learning approach enables the prediction of tool failure in advance, thereby minimizing the unexpected breakdown of tool and machine.

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2015

Dr. Radhika N and .Raghu, R., “Mechanical and tribological properties of functionally graded aluminium/zirconia metal matrix composite synthesized by centrifugal casting”, International Journal of Materials Research, vol. 106, pp. 1174-1181, 2015.

2015

V. Midhun and Dr. Radhika N, “Investigation of mechanical behaviour and tribological properties of coir and sugarcane bagasse fibers filled epoxy composites”, International Journal of Applied Engineering Research, vol. 10, pp. 37076-37081, 2015.[Abstract]


<p>Now a days the usage of natural fiber as reinforcement in polymers has gained significance due to its environmental nature like light weight, high strength, nearby obtainable and also reasonably economical. This current investigational study targets at learning the weight percentage of hybrid natural fiber reinforcement polymer composite material of coir and sugarcane bagasse fibers (10%, 15%) with epoxy resin as matrix in structural applications. The composite specimen was fabricated using hand lay-up practice to the dimension of 115mm x115mmx5mm. The mechanical properties like tensile strength and shore D hardness were approved out from the samples cut from the fabricated composite specimens. The tribological performance of hybrid polymer composite (7% of coir+3% of bagasse) filled epoxy composites were studied by means of Pin on Disc apparatus under dry sliding conditions. Major control factors mostly influencing the wear rate are recognized and the effect of wear constraints like load 10, 20, 30(N), sliding speed 1, 2,3(m/s), and sliding distance 500, 1000, 1500(m) on the sliding wear rate were examined by varying with three levels. A design of experiments based on the Taguchi technique was achieved to attain data in a precise way. An orthogonal array and Analysis of Variance (ANOVA) were practiced to examine the effect of process constraints on sliding wear behavior of these composites. Results revealed that hybrid polymer composite with (7% of coir+3% of bagasse) filled epoxy composites has the best tensile strength and shore D hardness number. Tribological results exposed that sliding distance have straight influence on wear rate (52.6%), pursued by sliding velocity (16.9%) and normal load (8.2%). © Research India Publications.</p>

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2015

Dr. Radhika N and Raghu, R., “Dry sliding wear behaviour of aluminium Al-Si12Cu/TiB2 metal matrix composite using response surface methodology”, Tribology Letters, vol. 59, pp. 1-9, 2015.[Abstract]


Abstract An aluminium Al-Si12Cu/TiB2 metal matrix composite was fabricated using the liquid metallurgy route, and its dry sliding wear characteristics were investigated under various sliding parameters. The titanium diboride (TiB2) particles (10 wt%, average size 50-60 μm) were incorporated into the matrix and its microstructural characteristic was examined. A five-level central composite design experiment was developed using response surface methodology; parameters such as load, velocity and sliding distance were varied in the range of 10-50 N, 1-5 m/s and 500-2500 m, respectively. Dry sliding wear tests were performed as per the experimental design using a pin-on-disc tribometer at room temperature. Significance tests, analyses of variance and confirmatory tests were performed to validate the developed model. Study of the microstructural characteristics revealed uniform dispersion of the reinforcement particles throughout the composite. The regression result showed that the developed model performed well in relating the wear process parameters with the response and predicting the wear behaviour of the composite. The surface plot showed that wear rate increased with increasing load at all velocities and distances, and decreased with increasing sliding distance. In the case of velocity, the wear rate decreased initially, increasing after the transition velocity had been reached. Scanning electron microscopy analysis revealed severe wear at a high load due to a higher level of deformation of the composite surface. © 2015 Springer Science+Business Media New York.

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2015

Dr. Radhika N and Raghu, R., “Experimental investigation on abrasive wear behavior of functionally graded aluminum composite”, Journal of Tribology, vol. 137, 2015.[Abstract]


<p>Functionally graded Al-Si12Cu/10 wt.% B4Cp metal matrix composite (MMC) has been fabricated under stir casting process followed by horizontal centrifugal casting method. The casting of length 170 mm, outer diameter 160 mm, and thickness 16 mm was obtained under the centrifugal speed of 1000 rev min-1. The microstructural evaluation was carried out on the surfaces at distance of 3, 6, 9, and 11 mm from the outer periphery of the casting to ensure the distribution of reinforcement particles, and the surfaces at same distance were tested for its hardness using microhardness tester. The microstructural results revealed that surface at a distance of 3 mm from the outer periphery has reinforcement concentration of 32% and surface at a distance of 11 mm has reinforcement concentration of 3%. The hardness of the surface was improved considerably according to the reinforcement concentration. The three-body abrasive wear test was conducted on the composite specimens as per L16 orthogonal array for parameters such as the load, speed, time, and reinforcement concentration. Each parameter was varied for four levels and the optimum level of each parameter was found out through signal-to-noise ratio analysis using "smaller-the-better" characteristics. The signal-to-noise ratio analysis revealed that load was the dominant parameter on the abrasive wear behavior followed by reinforcement concentration, speed, and time. The analysis of variance (ANOVA) result indicates the parameter that affects the response significantly and results were agreed with signal-to-noise ratio analysis. The regression equation was developed and results were validated using confirmation experiments. The worn-out surfaces were examined using scanning electron microscope (SEM) for observing the wear mechanism. Copyright © 2015 by ASME.</p>

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2015

Dr. Radhika N and Raghu, R., “Evaluation of dry sliding wear characteristics of LM 13 Al/B4C composites”, Tribology in Industry, vol. 37, pp. 20-28, 2015.[Abstract]


<p>The present paper labels the wear behaviour of the manufactured LM 13 aluminium/B4C metal matrix composites synthesized by means of liquid metallurgy technique. The B4C particles with size 33 μm diversified for the range of 0, 4, 8 and 12 wt-% were incorporated in the composite. The wear behaviour of the composites was studied as per L16 orthogonal array using pin-on-disc tribometer for various sliding conditions by varying the parameters such as load, velocity, sliding distance and wt-% of the reinforcement. Smaller-the-better characteristic was selected as the objective of the developed model and the optimum level of each parameter was detected. The influence of the parameters on the wear rate was known through analysis of variance. Regression model was developed and checked for adequacy using confirmation experiments. Scanning electron microscope analysis was done to study the worn morphologies of composite surface. The experimental results disclose that load was the major influencing parameter on the wear behaviour followed by wt-% of reinforcement, velocity and sliding distance. The worn-out surface interprets that rise in load yields a transition in the wear mechanism. The confirmatory results evident that Taguchi’s design as efficient statistical model by supporting the regression results with less error. © 2015 Published by Faculty of Engineering.</p>

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2015

Dr. Radhika N, Vijaykarthik, K. T., and Shivaram, P., “Adhesive wear behaviour of aluminium hybrid metal matrix composites using genetic algorithm”, Journal of Engineering Science and Technology, vol. 10, pp. 258-268, 2015.[Abstract]


<p>This paper involves the optimisation of the process parameters for the aluminium/alumina/graphite hybrid metal matrix composite to obtain the least wear rate during dry sliding process. The tribological properties of the composite have been studied and discussed. Experiments were carried out using pin-on-disc tribometer by varying the parameters such as load, velocity, distance &amp; the alumina composition of the composite and the wear rate for each input configuration was calculated. Using this empirical data, the regression equation was obtained using Artificial Neural Networks and this function was then optimised using Genetic Algorithm. The least wear rate was obtained for the composite with an alumina composition of 5 wt% © School of Engineering, Taylor’s University.</p>

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2015

Dr. Radhika N, G. Chandran, K., Shivaram, P., and Karthik, K. T. Vijay, “Multi-objective optimization of EDM parameters using grey relation analysis”, Journal of Engineering Science and Technology, vol. 10, pp. 1-11, 2015.[Abstract]


This paper involves the multi-objective optimization of process parameters of AlSi10Mg/9 wt% alumina/3 wt% graphite in Electrical Discharge Machining for obtaining minimum surface roughness, minimum tool wear rate and maximum material removal rate. The important machining parameters were selected as peak current, flushing pressure and pulse-on time. Experiments were conducted by selecting different operating levels for the three parameters according to Taguchi’s Design of Experiments. The multi-objective optimization was performed using Grey Relation Analysis to determine the optimal solution. The Grey Relation Grade values were then analysed using Analysis of Variance to determine the most contributing input parameter. On analysis it was found that peak current, flushing pressure and pulse-on time had an influence of 61.36%, 17.81% and 8.09% respectively on the optimal solution.

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2014

Dr. Radhika N and .Raghu, R., “Statistical modeling and analysing of wear behaviour of LM25 Al/B4C/Gr hybrid composites”, International Journal of Applied Engineering Research, vol. 9, pp. 8773-8776, 2014.

2014

Dr. Radhika N, .Shivaram, P., and Karthik, K. T. V., “Multi-objective optimization in electric discharge machining of aluminium composite”, Tribology in Industry, vol. 36, pp. 428-436, 2014.

2014

S. N Prabhakar, Dr. Radhika N, and Raghu, R., “Analysis of Tribological Behavior of Aluminium/B 4 C Composite Under Dry Sliding Motion”, Procedia Engineering, vol. 97, pp. 796-807, 2014.[Abstract]


This present study deals with the fabrication of aluminium/boron carbide metal matrix composite and investigation on its tribological behavior. The composite incorporated with 5 wt% of boron carbide particles with an average size 33 μmwas fabricated through stir casting process. The microstructure of this composite was examined and uniform distribution of reinforced particles in the matrix was observed. Wear experiments were conducted on pin-on-disc tester based on Taguchi's L27 orthogonal array using three process parameters such as applied load, sliding velocity and distance; each varied for three levels. Loads of 10 N, 20 N, 30 N; velocities of 1 m/s, 2 m/s, 3 m/s and distances of 1000 m, 1500 m, 2000 m were considered for analyzing the wear behavior of composite. Optimum parameters were found out using Signal-to-Noise ratio by choosing ‘Smaller-the-better’ characteristics for wear rate and coefficient of friction. Influence of individual parameter and their interactions on the responses was predicted using Analysis of Variance. Results depicted that both wear rate and coefficient of friction increases with load and decreases with velocity and distance. Worn out surfaces of the composite specimen were analyzed using Scanning Electron Microscope for predicting the wear mechanism. It was observed that, severe delamination occurred as applied load increased from 10 N to 30 N. This tribological analysis can be utilized to replace the conventional automotive materials with aluminium metal matrix composites having better wear characteristics.

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2014

T. Raviteja, Dr. Radhika N, and Raghu, R., “Fabrication and Mechanical Properties of Stir Cast Al-Si12Cu/B4C Composities”, International Journal of Research in Engineering and Technology, vol. 3, no. 7, pp. 343-346, 2014.

2014

Dr. Radhika N, Praveen, G., and P Rathan, G., “Study of wear behaviour of Al/(Al2O3P and SiCP) hybrid metal matrix composities”, Malaysian Journal of Science, vol. 33, 1 vol., pp. 78–88, 2014.

2014

Dr. Radhika N, R., S., and A., S., “Analysis of chip formation in machining aluminium hybrid composites”, E3 Journal of Scientific Research, vol. 2, pp. 09-15, 2014.

2014

Dr. Radhika N, Sudhamshu, A. R., and G. Chandran, K., “Optimization of electrical discharge machining parameters of aluminium hybrid composites using Taguchi method”, Journal of Engineering Science and Technology, vol. 9, pp. 502-512, 2014.[Abstract]


Metal matrix composites utilises the combined properties of the constituent material that finds applications in various fields. The present study investigates the influence of peak current, flushing pressure and pulse-on time on Electrical Discharge Machining of AlSi10Mg alloy reinforced with 3 wt% graphite and 9 wt% alumina hybrid metal matrix composites. Taguchi's Design of Experiment was used to analyse the machining characteristics of hybrid composites. Analysis of Variance and Signal-to-Noise ratio were used to determine the influence of input process parameters on the surface roughness, material removal rate and tool wear rate. Signal to Noise ratio and Analysis of Variance revealed that peak current was the most influential parameter on surface roughness followed by pulse on time and flushing pressure. For material removal rate, the major parameter was flushing pressure followed by peak current and pulse on time. The most significant parameter of tool wear rate was pulse on time followed by peak current and flushing pressure. Interaction terms also have significant effect on their output responses. © School of Engineering, Taylor's University.

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2014

Dr. Radhika N, Vaishnavi, A., and Chandran, G. K., “Optimisation of dry sliding wear process parameters for aluminium hybrid metal matrix composites”, Tribology in Industry, vol. 36, pp. 188-194, 2014.[Abstract]


The advancement in today's technology calls for the usage of superior material. A metal matrix composite has a unique characteristics to combine the various properties of the different materials present in the matrix composition, which enables it to be used for various high temperature applications where constrains could be overcome. The present study investigates the influence of applied load, sliding velocity and temperature on wear rate of AlSi10Mg alloy reinforced with 3 wt-% graphite and 9 wt-% alumina which was fabricated through liquid metallurgy route. The wear rate of this hybrid composite was investigated by performing dry sliding wear test on a pin-on-disc wear tester. The experiment was conducted for a constant sliding distance of 1500m. The influence of the various parameters on the wear rate was studied using Taguchi's Design of Experiment. An L9 orthogonal array was used for analysis of data. Signal-to-Noise ratio and Analysis of Variance were used to determine the ranking and percentage effect of input process parameters on wear rate respectively. Results revealed that load has the highest contribution on wear rate followed by temperature and sliding velocity. Worn-out wear surfaces were analysed using scanning electron microscope. © 2014 Published by Faculty of Engineering.

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2014

Dr. Radhika N and Subramanian, Rb, “Effect of ageing time on mechanical properties and tribological behaviour of aluminium hybrid composite”, International Journal of Materials Research, vol. 105, pp. 875-882, 2014.[Abstract]


Aluminium/alumina/graphite hybrid metal matrix composites prepared by using the stir casting technique were heat treated to enhance mechanical properties such as strength, hardness and wear resistance. The present study evaluates the effect of ageing time on the hardness, tensile strength and tribological behaviour of both unreinforced Al-Si10Mg alloy and aluminium hybrid metal matrix composites. Results for composite samples were compared with those of as-cast samples. Results showed that heat treated samples of alloy and composite showed higher hardness, tensile strength and tribological properties compared to both as-cast alloy and composite. Among the different ageing times employed, specimens aged for 4 hours showed maximum mechanical and tribological properties. Investigations of the worn surfaces were carried out using scanning electron microscopy to understand the wear mechanism.

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2013

Dr. Radhika N, S Prasat, V., and Subramanian, R., “Wear behaviour of Aluminium/alumina/graphite hybrid metal matrix composite using Taguchi's techniques”, Industrial Lubrication and Tribology, vol. 65, pp. 166-17, 2013.

2013

Dr. Radhika N and .Subramanian, R., “Influence of process parameters on wear behaviour of hybrid aluminium composites”, International Journal of Operations Systems and Human Resource Management, vol. 3, pp. 27-35, 2013.

2013

Dr. Radhika N and Subramanian, Rb, “Effect of reinforcement on wear behaviour of aluminium hybrid composites”, Tribology - Materials, Surfaces and Interfaces, vol. 7, pp. 36-41, 2013.[Abstract]


<p>Aluminium metal matrix composites are among the recent developments in engineering applications to meet the present day need of light weight, high strength/weight ratio and good wear properties. In the present study, AlSi10Mg alloy reinforced with 3, 6 and 9 wt-% alumina with constant 3 wt-% graphite particles was produced by stir casting technique. Microstructural investigations as well as evaluation of mechanical properties such as hardness, tensile strength and double shear strength were conducted on composites and unreinforced alloy specimens. Tribological behaviour of hybrid composites was studied using pin on disc test machine. Wornout surfaces were analysed using scanning electron microscopy, and wear debris were analysed using X-ray diffraction. Results revealed that the mechanical properties of hybrid composites were higher than unreinforced alloy. Dry sliding wear test results indicated that the aluminium alloy reinforced with 9 wt-% alumina and 3 wt-% graphite has highest wear resistance compared to unreinforced alloy. © 2013 W. S. Maney &amp; Son Ltd.</p>

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2013

Dr. Radhika N, Subramaniam, Rb, and Senapathi, S. Ba, “Machining parameter optimisation of an aluminium hybrid metal matrix composite by statistical modelling”, Journal of Industrial Lubrication and Tribology, vol. 65, pp. 425-435, 2013.[Abstract]


<p>Purpose - The objective of this research is focused on the design of a new hybrid composite as well as to analyse the optimum turning conditions to minimise the surface roughness and work piece surface temperature, thereby increasing the productivity. Design/methodology/approach - Mechanical properties such as hardness and tensile strength of Al-Si10Mg alloy reinforced with 3, 6 and 9?wt.% of alumina along with 3?wt.% of graphite prepared by stir casting method have been evaluated. The present study addresses the machinability parameter optimisation of Al alloy-9 per cent alumina-3 per centgraphite. Experiments were conducted based on the Taguchi parameter design by varying the feed (0.1, 0.15 and 0.2?mm/rev), cutting speed (200, 250 and 300?m/min) and depth of cut (0.5, 1.0 and 1.5?mm). The results were then analysed using analysis of variance (ANOVA). Findings - Mechanical properties of the hybrid composite increases with reinforcement content. The surface roughness decreases with increasing cutting speed and conversely increases with increasing feed and depth of cut. The work piece surface temperature increases as cutting speed, feed and depth of cut increases. The ANOVA result reveals that feed plays a major role in minimising both surface roughness and surface temperature of work piece. The cutting speed and depth of cut follow feed in the order of importance, respectively. Research limitations/implications - The vibration of the machine tool is a factor which may contribute to poor quality characteristics. This factor has not taken been into account in this analysis since major vibrations in the machine are induced due to the machining process. Practical implications - Design and development of new hybrid metal matrix composites (HMMCs) with a detailed analysis on machining conditions. The findings could help in the production of composite with a higher degree of surface finish. This will enable the adoption of HMMCs as industrial product for mass scale production. Originality/value - Good quality characteristics were achieved using optimum machining conditions arrived using a statistical modelling. Copyright © 2013 Emerald Group Publishing Limited. All rights reserved.</p>

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2013

Dr. Radhika N, S Senapathi, B., Subramaniam, R., Subramany, R., and Vishnu, K. N., “Pattern recognition based surface roughness prediction in turning hybrid metal matrix composite using random forest algorithm”, Industrial Lubrication and Tribology, vol. 65, no. 5, pp. 311–319, 2013.[Abstract]


The purpose of this paper is surface roughness prediction using pattern recognition for the aluminium hybrid metal matrix composite (HMMC).

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2012

Dr. Radhika N, Subramanian, R., S Prasat, V., and Anandavel, B., “Dry sliding wear behaviour of aluminium/alumina/graphite hybrid metal matrix composites using Taguchi's techniques”, Industrial Lubrication and Tribology, vol. 64, pp. 359–366, 2012.[Abstract]


Recent trends in material science show a considerable interest in the manufacturing of metal matrix composites to meet the stringent demands of lightweight, high strength and corrosion resistance. Aluminium is the popular matrix metal currently in vogue that can be reinforced with ceramic materials such as particulates to meet the desired property. The purpose of this paper is to fabricate hybrid metal matrix composites to improve the dry sliding wear resistance and to study of the effect of sliding speed, load and reinforcement (alumina and graphite) on wear properties, as well as its contact friction.

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2011

Dr. Radhika N, Subramanian, R., S Prasat, V., and , “Tribological behaviour of aluminium/alumina/graphite hybrid metal matrix composite using Taguchi’s techniques”, Journal of Minerals and Materials Characterization and Engineering, vol. 10, pp. 427-443, 2011.[Abstract]


Tribological behaviour of aluminium alloy (Al-Si10Mg) reinforced with alumina (9%) and graphite (3%) fabricated by stir casting process was investigated. The wear and frictional properties of the hybrid metal matr ix composites was studied by performin g dry sliding wear test using a pin-on-disc wear tester. Experiments were conducted based on the plan of experiments generated through Taguchi’s technique. A L27 Orthogonal array was selected for analysis of the data. Investigation to find the influence of applied load, sliding speed and sliding distance on wear rate, as well as the coefficient of friction during wearing process was carried out using ANOVA and regression equations for each response were developed. Objective of the model was chosen as ‘smaller the better’ characteristics to analyse the dry sliding wear resistance. Results show that sliding distance has the highest influence followed by load and sliding speed. Finally, confirmation tests were carried out to verify the experimental results and Scanning Electron Microscopic studies were done on the wear surfaces More »»

2011

SaVenkat Prasat, Subramanian, Rb, Dr. Radhika N, Anandavel, Bb, Arun, La, and Praveen, Na, “Influence of parameters on the dry sliding wear behaviour of aluminium/fly ash/graphite hybrid metal matrix composites”, European Journal of Scientific Research, vol. 53, pp. 280-290, 2011.[Abstract]


The influence of parameters like load, sliding speed, reinforcement content and their interactions on dry sliding wear rate of aluminium/fly ash/graphite hybrid metal matrix composites was investigated. The design of experiments (DOE) approach using Taguchi method was employed to analyze the wear behaviour of hybrid composites. A pinon-disc apparatus was used to conduct the dry sliding wear tests. Signal-to-noise ratio and analysis of variance (ANOVA) were used to investigate the influence of parameters on the wear rate, and correlation between them was established by a multiple linear regression model. The wear rate of the hybrid composites can be predicted by the multiple linear regression model. It was determined that load was the most significant parameter influencing the wear rate of the hybrid composites, followed by sliding speed and fly ash content. There was an increase in the wear rate of hybrid composites with increasing load, but the wear rate decreased with increase of sliding speed and fly ash content. The worn surfaces of the composite pins were analyzed by scanning electron microscopy to study the wear mechanisms. At high sliding speeds, mechanically mixed layer (MML) and a lubricating film of graphite were formed between the composite pin and the steel counterface and they reduced the chance of direct metallic contact, thereby lowered the wear rate. The wear mechanism changes from severe abrasive wear to mild oxidative wear at high sliding speeds. The incorporation of fly ash and graphite particles as reinforcements improved the tribological characteristics and caused a reduction in the wear loss of the hybrid composites. © EuroJournals Publishing, Inc. 2011.

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2011

V. S. Prasat, Subramanian, R., Dr. Radhika N, and Anandavel, B., “Dry sliding wear and friction studies on AlSi10Mg-fly ash-graphite hybrid metal matrix composites using Taguchi method”, Tribology - Materials, Surfaces and Interfaces, vol. 5, pp. 72-81, 2011.[Abstract]


The aim of the investigation is to study the influence of parameters such as sliding distance, sliding speed, load and fly ash content on dry sliding wear loss and coefficient of friction (COF) of AlSi10Mg-Fly ash-graphite hybrid composites using Taguchi method. A pin-on-disc wear testing equipment was used to conduct the dry sliding wear tests on the hybrid composite produced through the liquid metallurgy route. Signal to noise ratio response analysis and analysis of variance were used to investigate the influence of parameters, and correlation between the parameters was established by multiple linear regression models. It was determined that sliding distance was the most dominant factor influencing the wear and COF of hybrid composites. There was a decrease in wear with increases in sliding speed and fly ash content. However, the COF of composites increased with increasing load, but decreased with increases in sliding distance, sliding speed and fly ash content. At higher sliding speeds, a mechanically mixed layer (MML), containing fractured fly ash particles and oxides of aluminium and iron form between the pin and the counterface. This MML helps to reduce the chance of direct metallic contact, thereby lowering the wear loss and COF. Multiple linear regression models were developed which could be effectively used to predict the wear loss and COF of the hybrid composites. Abrasive wear was the dominant wear mechanism at low loads and when the load was increased to 26?98 N, the wear mechanism changed to mixed abrasion-delamination wear with a drastic increase in the wear loss of the hybrid composite. Mild oxidative wear was predominant at high sliding speeds (3 m s-1) and lower loads. © 2011 W. S. Maney & Son Ltd.

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2005

Dr. Radhika N, Srinivasan, P. S. S., K. Kumar, S., and M. Davidson, J., “Determination of weld process parameters for precisional welding: A DOE & FEA Approach”, National Journal of “Manufacturing Technology Today”, pp. 3-6, 2005.

Publication Type: Conference Paper

Year of Publication Title

2015

S. M. Chandrabose and Dr. Radhika N, “Analysis of the Machining Characteristics on Surface Roughness of Functionally Graded Aluminium Metal Matrix Composite”, in International Conference on ‘Advanced Engineering and Technology for Sustainable Development, Karpagam College of Engineering, Coimbatore, 2015, vol. 10, pp. 14856-14861.

2014

Dr. Radhika N and Prabhakar, S., “Influence of Cutting Parameters on Surface Roughness of Aluminium Hybrid Composites”, in International Conference on “Modeling, Optimisation and Computing, Noorul Islam University, Kumaracoil, Kanyakumari Dist, India, 2014.

2014

Dr. Radhika N and .Raghu, R., “Statistical Modeling and Analysing of Wear Behaviour of LM25 Al/B4C/Gr Hybrid Composites’”, in International Conference on “Modeling, Optimisation and Computing, Noorul Islam University, Kumaracoil, Kanyakumari Dist, 2014.

2013

Dr. Radhika N, .Shivaram, P., and Karthik, K. T. V., “Electric Discharge Machining of Aluminium Hybrid Metal Matrix Composite”, in International Conference on “Recent Advances in Material Processing Technology, National Engineering College, Kovilpatti, India, 2013.

2011

K. .N.Vishnu, Subramany, R., and Dr. Radhika N, “Pattern Recognition Model for Predicting Surface Roughness in Machining Aluminium Hybrid Metal Matrix Composite using Decision Tree Algorithm”, in Recent Trends in Communication,Computation and Signal Processing, Amrita Vishwa Vidyapeetham, Coimbatore, 2011.

2011

Dr. Radhika N and .Subramanian, R., “Influence of Process Parameters on Wear Behaviour of Hybrid Aluminium Composites”, in International Conference on “Simulation Modeling and Analysis, 2011.

2004

Dr. Radhika N and .Muthuraman, V., “Thermal Analysis of Aluminium-12% Wt. Silicon Alloy Piston Casting using FEM”, in National Conference on “Global Technologies in Manufacturing and Thermal Sciences, Sethu Institute of Technology, Kariapatti, 2004.

2004

Dr. Radhika N, Srinivasan, P. S. S., and .Prakash, D., “Thermal Analysis of Welding using FEA”, in National Conference on “Recent Trends in Manufacturing, Modeling and Analysis, St. Joseph’s College of Engineering Chennai, Feb-2, 2004.

2004

Dr. Radhika N, .Prakash, D., Srinivasan, P. S. S., and .Tamizharasan, T., “Effect of Vane Angle in Forward Curved Centrifugal Pump-A FEA Approach”, in National Conference on “Modeling and Analysis of Production Systems, National Institute of Technology, Trichy, 2004.

2004

Dr. Radhika N, .Tamizharasan, T., .Prakash, D., and .Anadhakrishnan, V., “Heat Transfer Analysis of Engine Fins using FEA”, in National Conference on “Modeling and Analysis of Production Systems, National Institute of Technology, Trichy, 2004.

2004

Dr. Radhika N, .Prakash, D., .Jegadheesan, C., and .Tamizharasan, T., “Parametric Study on the Performance of Centrifugal Pump – Forward Vane Type Using DOE”, in National Conference on “Fabrication and Processing of Composites and Light Materials, Annamalai University, 2004.

2003

Dr. Radhika N, .Jagadessan, C., and .S.S.Srinivasan, P., “Determination of Optimum Weld Quality using DOE and FEA”, in National Conference on “Quality Engineering and Management, Kumaraguru College of Technology, Coimbatore, 2003.

Publication Type: Conference Proceedings

Year of Publication Title

2014

Dr. Radhika N, Prabhakar, N. S., and .Raghu, R., “Analysis of Tribological Behaviour of Aluminium/ B4C Composite Under Dry Sliding Motion”, International Conference on “12th Global Congress on Manufacturing and Management, vol. 97. VIT University, Vellore, India, pp. 796-807, 2014.

2014

Dr. Radhika N and .Raghu, R., “Three Body Abrasion Wear Behaviour of Functionally Graded Aluminium/B4C Metal Matrix Composite Using Design of Experiments”, International Conference on 12th Global Congress on Manufacturing and Management, vol. 97. VIT University, Vellore, pp. 713–722, 2014.

2011

Dr. Radhika N, Subramany, R., and .N.Vishnu, K., “Studies On Tree Based Classifiers for the Prediction of Surface Roughness In Turning Aluminium Metal Matrix Composites”, a. Dr.MGR university , 2011.

Workshops/Short-term Courses Attended

  • National Workshop on “Finite Element Analysis” organized by Karpagam College of Engineering during October 2003.
  • Workshop on “Advanced Welding Techniques” (hotel residency, Coimbatore), organized by Indian welding society, Coimbatore centre, 2005.
  • National Workshop on “Advanced Materials and Their Properties” organized by Indian Welding Society and Amrita IWS student Forum, Department of Mechanical Engineering, Amrita School of Engineering, Coimbatore, during March 20-21, 2014.
  • National Workshop on “Recent Trends in Manufacturing” organized by Department of Mechanical Engineering, Amrita School of Engineering, Amrita Vishwa Vidyapeetham, Coimbatore, during March 27-28, 2014.
  • National workshop on “ Topics in Engineering Failure Analysis” organized by Amrita School of Engineering, Amrita Vishwa Vidyapeetham, Coimbatore and Society for Failure Analysis, Hyderabad, during April 26, 2014.
  • Short-term course on “Thermal and CFD Analysis using ANSYS” conducted by KEC-AU FRG Center for CAD/CAM during May 2002.
  • Short-term Training Programme on “Applications of Computational Fluid Dynamics (CFD) with Special Reference to Food Industries” for two weeks organized by Kongu Engineering College during March 2004.
  • All India Seminar on “Composites for Engineering Applications” organized by The Institution of Engineers (INDIA) Coimbatore local centre under the Aegis of Interdisciplinary Coordination Committee held at PSG College of Technology, Coimbatore, during July 20-21, 2012.
  • Innovate India 2015 conference on “Make in India: Opportunities Through Innovation” organized by National Research Development Corporation, New Delhi and PSG College of Technology, Coimbatore, during  February 25-26, 2015.