Tribological properties of Aluminium Metal Matrix Composites (AA7075 Reinforced with Titanium Carbide (TiC) Particles)

Abstract

In the present work aluminum matrix composites (AMMCs), AA7075 Alloy as the matrix metal and Titanium carbide (TiC) particles (2-10%) with an average particulate size of 2μm as reinforced material were processed by stir casting route. Computerized pin on disc wear tester was used for wear test with counter surface as EN32 steel disc (58-60 HRC) and cylindrical pin as the composite specimens. The wear rate in terms of weight loss per unit sliding distance, coefficient of friction and volume loss were obtained for the matrix metal and composites. The results of composite shows better wear resistance than matrix metal. The microstructural characterization of worn surface was investigated using SEM. Weight loss of samples was calculated and the variation of cumulative wear loss with sliding distance has been found to be uniform for both the matrix metal and the composites. It was also observed that the wear rate is low for composites compared to matrix metal. Further, it was noted from the experimentation that the wear rate decreases with increasing weight fraction of TiC and coefficient of friction decreases with increasing sliding velocity and weight fraction of TiC. SEM-XRD analysis revealed the presence of TiC and other phases. The better wear properties (wear rate, coefficient of friction and wear factor) was observed with 8 wt% TiC composite compared to other composites as well as matrix metal.