Process-Composition Design of Hypoeutectic Aluminum-Silicon Alloy for High Performance Wear Resistance Application

This study investigates the process-composition design of hypoeutectic aluminium-silicon alloys aimed at improving the wear behaviour of the alloy for tribological application. Hypoeutectic Al-Si alloys with percentage composition of silicon ranging from 3 – 7.5% were cast at varying pouring temperatures of 700, 750 and 8000C. The impact of the process-composition parameters on wear rate and the microstructures of the alloy were determined using tribor testing apparatus and scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) respectively. The results obtained show that increasing silicon content from 3 – 7.5% significantly improved the wear rate of the alloy from 0.0360 – 0.0120 mg/m with optimum pouring temperature value at 7000C. The SEM micrographs indicate that higher percentage composition of silicon yielded the formation of more numbers of primary silicon phases with intermetallic phases that reduced material loss while optimum pouring temperature influenced solidification rate leading to a refined uniform homogeneous phases distributed in the microstructures. It was concluded that process parameter optimization carefully tailored through combination of silicon percentage composition and pouring temperature enhances the wear performance of Al-Si alloys for engineering applications in wear-critical environment.