Assessment of Mechanical and Tribological Characteristics of A356 Reinforced with x wt% CaB6 Composites

This paper involves the study of mechanical and tribological characteristics of as-cast aluminium A356 metal matrix composites reinforced with calcium hexaboride (CaB6) particulates. Two Composite specimens with varying reinforcement weight percentages of 2.5% and 5% were fabricated using stir casting method. Mechanical properties (hardness and tensile strength) of as-cast and composite specimens were studied, and its tensile fracture surface behaviours were examined under scanning electron microscope. In addition, wear and friction characteristics were observed at dry sliding atmospheric condition for as-cast and composite specimens. Wear and friction tests were performed with three different loads (10 N, 20 N and 30 N) and two sliding velocities (1 m/s and 3 m/s) parametric condition. The responses of coefficient of friction and wear rate measurements were recorded for further analysis. Worn out surfaces of test samples were analysed through SEM (Scanning Electron Microscope) and the wear mechanisms were studied. From experiments it is found that, the hardness and tensile strength had increased for higher weight percentage added composites (5% CaB6). The same higher weight percentage composite specimen exhibited lower wear rate and higher coefficient of friction than the other combinational test samples. The developed higher weight percentage added composite sample is recommended for replacing automobile components.