Study of Mechanical Properties & Residual Stresses on Post Wear Samples of A356-SiC Metal Matrix Composites

Abstract

Aluminium alloy (A356) - Silicon carbide (SiC) metal matrix composites were fabricated using liquid metallurgy technique. SiC particles were coated with copper by electroless process. Microstructural details clearly demonstrated that Cu coating on SiC particle was responsible for a good metallurgical bonding between A356 and SiC. The increase in SiC content from 5 to 15 wt% in A356-SiC MMC's resulted an improvement of 46% and 15% in hardness and tensile properties respectively.The Sliding wear performance of A356 and A356-SiC suggests that SiC content was responsible for improved wear results as expected. Wear caused internal permanent strains and led to the generation of residual stresses. Residual stress measurements on post wear specimens revealed that the nature of stress was compressive and its magnitude decreased as SiC content was increased. This compressive residual stress is the indicative of tensile strains generated during wear in the composite.