Tribological Study of AA6061-Based Hybrid Composite Reinforced with Graphene, TiO2, and SiC Fabricated by Hot Isostatic Pressing

This investigation aims at the fabrication and characterization of a hybrid composite material using aluminum alloy 6061 (AA6061) as the matrix. AA6061 is reinforced with hard ceramic particles such as titanium dioxide (TiO2), silicon carbide (SiC), and soft graphene powder. A constant fraction of 10 and 3 wt%, respectively, of SiC and TiO2 made up the ceramic reinforcement phase. The fabrication process utilizes HIP where HIP parameters such as temperature and pressure along with graphene wt% were varied. The primary focus was to improve the wear behavior of AA6061 for various industrial applications. Mechanical properties were evaluated by microhardness and wear tests to identify optimal conditions for maximizing wear resistance. At higher HIP processing temperatures and graphene content, the microhardness was found to be relatively high. SEM analysis revealed good bonding between the matrix and reinforcement phases and a fine distribution of both phases. The wear test results exhibited an initial decrease in wear rate with increasing graphene content, followed by an increase beyond a certain wt% of graphene. Finally, the Taguchi optimization technique was applied to refine the process parameters and enhance the wear performance of composites. This study provides insights into the fabrication, characterization, and optimization of AA6061-based hybrid composites with improved wear properties and mechanical performance.