R Pramod, Assistant Professor, Department of Mechanical Engineering, Amrita School of Engineering, Bengaluru provided expert input to the research thesis, Experimental Characterization of Mechanical and Tribological Properties of Carbon Based Composite.
The paper was co-authored by S. D. Kavitha, Assistant Professor at Alliance University, Bengaluru and D. M. Shivanna, Assistant Professor at Dayananda Sagar College of Engineering, Bengaluru.
The thesis was presented in an international conference, Advanced Materials, Manufacturing, Management & Thermal Sciences (AMMMT-2013) hosted by Siddaganga Institute of Technology, Tumkur.
The paper suggests an approach to combine Carbon and Nomex laminate fibers in order to compliment the drawbacks on using them individually. The composite may be well suited for aerospace and allied industries, since the materials used in aerospace require exceptional performance with high strength or heat resistance, long-term reliability, and high resistance to fatigue.
Traditionally, aluminum alloys have been dominant in the aerospace industry ever since the introduction of metal skinned aircrafts. However, this paper suggests that the Carbon Nomex composites may be a potential alternative in the future.
Carbon fibers possess low weight, high strength and high temperature resistive virtues while Nomex fibers have high tensile strength, flexure and resistance to wear.
Combining the two components into a single laminate can potentially produce a composite that exhibits high tensile strength, low weight, high wear resistance and increased temperature resistance.
A matrix of Araldite LY556 and Aradur HY951 is reinforced by Nomex T410 sheet, Carbon fiber and E-Glass fiber. Araldite LY556 is a medium viscous, unmodified liquid epoxy resin based on Bisphenol-A while Aradur HY951 is a low viscous, unmodified aliphatic polyamine.
Epoxy resin of density 1.18g.cm-3 and hardener of density 0.98g.cm-3, mixed in the ratio 9:1, reinforced by 4mm thick, 305 mm square laminate subsuming stacked layers of 0.24mm thick carbon sheets, 0.18mm thick Nomex sheet, 0.2mm thick E-glass fiber, are subjected to experimentation and testing as per the ASTM International standards for tensile (D3039), compressive (D3410) strengths, hardness (D785-08) and Wear resistance (G99).
It was inferred that among the stacks having various combinations of layers of constituents, stacks having more number of Carbon fiber depicted higher tensile strength, while stacks having more Nomex fiber portrayed higher compressive strength.
A change in wear rate was scrutinized with a change in Nomex composition. Carbon-Nomex composites characterize lesser wear rate and strength value almost equal to that of aluminium.
September 7, 2013
School of Engineering, Bengaluru