Mechanical and tribological properties of Al7475-SiCp composites by stir casting method and wear rate modeling using RSM

Abstract

The microstructure, mechanical and wear properties of the Al 7475-SiCp composites and to investigate the effects of SiC micro-particles reinforcement with alloy have been studied. Al 7475-SiCp composites have been developed by a stir casting method. The SiCp size in the range of 15–40 µm with weight.% of 0, 5, 10 and 15 were injected in molten Aluminum 7475 alloy in argon gas environment and stirrer using a mechanical method at 450 rpm to ensure uniform distribution of SiC particles. The mechanical properties such as hardness and compressive strength of the composites were found to be gradually improved with the addition of 5–15% SiCp reinforcement. The ultimate tensile and impact strength increased with 10% of SiCp reinforcement. For modeling the wear rate, the experiments were conducted in Pin-on Disc tribometer at room condition. A three-level central composite design with response surface methodology was used to reduce the experimental conditions and to predict the abrasive response of wear rate through the development of mathematical models. The model developed is efficiently predicted the rate of wear at 95% confidence level and the entire model validate with analysis of variance.