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: PhD Mechanical Engineering
    Anna Vishwa Vidyapeetham, Coimbatore.
  • 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 Publication Type Title

2017

Journal Article

Dr. Radhika N and K. Charan, S., “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, pp. 1-8, 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

Journal Article

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, pp. 1-8, 2017.[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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2017

Journal Article

Dr. Radhika N, “Fabrication of LM25/SiO2metal matrix composite and optimization of wear process parameters using design of experiment”, Tribology in Industry, vol. 39, 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

Journal Article

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”, Journal of Tribology, vol. 139, 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

Journal Article

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 [Untersuchungen des Abriebverschleißverhaltens von funktionell gradiertem Aluminium”, Materialwissenschaft und Werkstofftechnik, vol. 48, pp. 600-610, 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

Journal Article

Dr. Radhika N and Priyanka, M. L. Venkata, “Investigation of adhesive wear behaviour of zirconia reinforced aluminium metal matrix composite”, Journal of Engineering Science and Technology, vol. 12, 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

Journal Article

R. Nithesh, Dr. Radhika N, and S. Sunder, S., “Mechanical Properties and Adhesive Scuffing Wear Behavior of Stir Cast Cu-Sn-Ni/Si3N4 Composites”, Journal of Tribology, vol. 139, 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. Copyright © 2017 by ASME.

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2016

Journal Article

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 »»

2016

Journal Article

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, pp. 1-13, 2016.[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

Journal Article

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

Journal Article

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, pp. 1-8, 2016.[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. More »»

2016

Journal Article

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

Journal Article

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, pp. 1-8, 2016.[Abstract]


ABSTRACTAluminum 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. More »»

2016

Journal Article

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

Journal Article

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, pp. 1-11, 2016.[Abstract]


ABSTRACTFunctionally 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. More »»

2016

Journal Article

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, 2016.[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 »»

2016

Journal Article

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, 2016.[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. More »»

2016

Journal Article

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

Journal Article

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 »»

2015

Journal Article

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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2015

Journal Article

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

Journal Article

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

Journal Article

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

Journal Article

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

Journal Article

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

Journal Article

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

Journal Article

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

Journal Article

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

Journal Article

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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2014

Journal Article

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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2014

Journal Article

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

Journal Article

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

Journal Article

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

Journal Article

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

Journal Article

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

Journal Article

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

Journal Article

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

Journal Article

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.

2013

Journal Article

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

Journal Article

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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2013

Journal Article

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

Journal Article

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

Journal Article

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.

2012

Journal Article

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

Journal Article

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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2011

Journal Article

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

Journal Article

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 »»

2005

Journal Article

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 Proceedings

Year of Publication Publication Type Title

2016

Conference Proceedings

J. Dinesh, G. Ashraf, M., and Dr. Radhika N, “Fabrication and characterization of Al LM25/TiB2 in-situ composites”, International Conference on Advanced Engineering and Technology for Sustainable Development. Karpagam College of Engineering, Coimbatore, 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. More »»

2014

Conference Proceedings

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.

2014

Conference Proceedings

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.

2011

Conference Proceedings

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.

Publication Type: Conference Paper

Year of Publication Publication Type Title

2015

Conference Paper

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

Conference Paper

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.

2014

Conference Paper

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.

2013

Conference Paper

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

Conference Paper

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.

2011

Conference Paper

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.

2004

Conference Paper

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.

2004

Conference Paper

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

Conference Paper

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

Conference Paper

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

Conference Paper

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.

2003

Conference Paper

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.

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.
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