Mechanical Properties and Wear Behaviour of Al2O3/SiCp Reinforced Aluminium-Based MMCs Produced by the Stir Casting Technique

Abstract

In this study, initially Al2O3/SiC powder mix was prepared by reacting of aqueous solution of aluminium sulphate, ammonium sulphate and water containing SiC particles at 1200°C. 10 wt% of this hybrid ceramic powder with different sized SiC particles was added to a liquid Al matrix alloy during mechanical stirring between solidus and liqudus under inert conditions. Then hybrid Metal Matrix Composites (MMCs) was produced. The effect of reinforced particle size on tensile strength, bending strength, hardness resistance and wear resistance properties of hybrid reinforced MMCs were investigated. The mechanical test results revealed that bending, tensile strength and hardness resistance of the composites increased with decrease in ductility, with decrease size of the reinforcing SiC particulates in the aluminium alloy metal matrix. The wear behaviour of the hybrid ceramic reinforced aluminium matrix composites was investigated using pin-on-disc test at room temperature under dry conditions. Wear tests showed that the wear resistance of MMCs increased with increasing reinforced Al2O3/SiC particle size. Comparing the fine particle size MMCs with the coarse particle size MMCs were easily pulled out whole from the matrix. Microstructural examination showed that as well as coarse SiC particle reinforcement, a fine alumina particle reinforcement phase was observed within the aluminium matrix (A332).