Shashi Kumar M. E.

Al-6061 and Nickel, individually serve for various requirements of their multitude mechanical characteristics and ideal chemical properties. In present scenario, Al-6061 has captured the attention of both academia and industrialists’ interest for its usage in multiple fields such as transportation, construction and similar engineering industries. The primary intention of this research is to investigate the properties of mechanical strength ofAl-6061 subjected to Electroless Nickel (EN) coating. The test specimens are prepared as per ASTM norms, and have been evaluated by the addition of EN coating layers of thicknesses 0µ, 2µ, 4µ, 6µ and 8µ. The EN coated specimens are tested for investigating various mechanical properties. These investigations are performed as per ASTM standards. The results thus obtained reveal that, the properties of mechanical strength, such as elastic strength and UTS increases up to 6µ thickness of EN coated specimen. The characteristics viz. hardness and impact energy absorption of a material increases with higher EN coating layer thickness. It has been observed that there is improvement in the properties of Al6061 coated with EN when compared to the other coated materials as well as non-coated Al-6061. The EN coated Al6061finds its broad applications in the field of structural and defence/aviation sectors.

Graphene and E-glass fibres are one of the key materials used currently due to their unique chemical and mechanical properties. Lately graphene has attracted many researchers across academic fraternity as it can yield better properties with lesser reinforcement percentages. The current research emphasizes on the development of graphene-based nanocomposites and its investigation on dielectric applications. The composites were fabricated by adding graphene reinforcements from 1%-3% by weight using conventional Hand-lay process. A thorough investigation was carried out to determine the dielectric behaviour of the nano-composites using impedance analyser according to ASTM standards. The dielectric measurements were carried out in the temperature range of 300K to 400K in a step of 20K. The current research proposes the material for application in capacitor industry as the sample of 2.5% weight fraction showed highest value of K with 14 at 26.1 Hz and 403K

E-glass fibre and Bisphenol-A have a wide range of applications when it comes to fabricating composite laminates due to their superior chemical and mechanical properties. Bisphenol-A can alter insulation properties at lower filler volume. In the current endeavour, an investigation was made into the effect of Bisphenol concentration on mechanical and insulation properties. The composites have different compositions of Bisphenol in the range of 1% to 3%. Conventional hand layup process was used to fabricate the laminates and were tested as per ASTM. The experimental results show that there is only marginal increase in hardness and tensile strength with increase in weight proportions from 1% to 3% of Bisphenol powder and it can be concluded that the Bisphenol is not contributing to the significant changes in Mechanical properties. SEM analysis was carried out to study the morphological features of the tested specimens. Further, the stellar role played by the addition of Bisphenol is observed through the tests carried out for determining the insulation properties. It was observed that there was a significant increase in the insulation properties of the laminates with the increase in the weight proportions of Bisphenol and it is attributed that the laminates thus fabricated will find applications in the industries that manufacture thermal resistant materials. © IAEME Publication.

A study on mechanical and fracture properties, through the experimentation techniques has been carried out on a Al 7075-T6 and it coated with an Electroless Nickel deposits of 10–20 μm in coating thickness. In the recent years there has been considerable interest in the Electroless Nickel plating due to its extensive use in electronics, automobiles, aerospace and other industries. Electroless Nickel plating is a controlled autocatalytic reduction of nickel ions using suitable reducing agent such as sodium hypophosphite. ASTM Standard – E 399 for plane strain fracture toughness determination was adhered in this investigation. The results obtained, show that the EN coating can give rise to a significant improvement in the fracture behavior (performance) of the substrate and also it has shown that EN coating exhibit a very good adhesive property to the alloy material when the tensile stresses exceeding the yield strength are applied to the system and performance of these pretreatments was studied by SEM analysis.

Fracture toughness, Hardness and Tensile Strength of the Aluminum alloy 7075-T6 coated with Cadmium with varying thickness of 10μ and 20μ were investigated. Electroplating Cadmium coating process gives excellent corrosion resistance, provides low coefficient of friction which increases the surface hardness of the material. It also provides a uniform and dense coating, in many cases, maintains surface finish as it was before plating. The specimens prepared in line with ASTM E-8M and E-399 standard were subjected to various tests. The results shows thatthe hardness of the EC coted specimens has increased by 10% and increases with increase in thickness, butthe thicker the EC coating, more brittle is the material. The Ultimate Tensile Strength also increased by 5% compared to the uncoated counterpart. There was a steep increase in plain strain fracture toughness with the increase in the coating thickness for the Aluminum 7075-T6 alloy in TL orientation. The crack growth was Unstable due to the strong adhesion between the EC coating and the alloy.

Glass fibre-reinforced plastics (GFRP) composite materials are extending the application horizons of designers in all branches of engineering. The present work is focused on development and determination of mechanical and dielectric properties of hybrid polymer composites of Nomex and High Silica Glass fabricated through handlay process. Five laminates each were fabricated for four different stacking orders with an average of 55% matrix contents. The polymeric composite was tested for mechanical and dielectric properties. It is found that the hardness was boosted in the laminate with the presence of more layers of High Silica glass fibers, presence of higher number of Nomex contributed for an increase in the compression strength and High Silica glass fibers and Nomex had an equal effect in increasing flexural strength of the composite. The Nomex and E-glass fibers present in the core of the composite covered by High Silica glass on the outer layer of the composite offered very good dielectric strength and surface resistivity for the composite and the absence of E-glass fibers have enhanced the dissipation factor. Further all laminates showed a greater stability towards chemical attack and temperature stability was observed up to 300° C. © 2017 Elsevier Ltd. All rights reserved.