Effect of Cu content on the microstructures and wear performance of Al-Si-Cu-Ni-Mg alloy based SiC reinforcement composites

In this research, the matrix, namely Al-12Si-xCu-1Ni-1Mg (x = 2, 4, 6 wt%), was designed. The Al/SiC composites containing 20 vol% SiC particles was prepared by stirring casting. The microstructures (SEM and EDS), hardness, tensile strength, wear performances under room temperature (pin-on-disk) and elevated temperature (ball-on-disk) of Al/SiC composites were tested. SEM and EDS analysis confirms the increases of precipitate phases of the composites after heat treatment, which improves the hardness and wear properties at room temperature. Addition of 4 wt%Cu to the matrix possesses the best wear properties at room temperature, while 6 wt% Cu to the matrix possesses the best wear properties at elevated temperature.