IMPROVEMENT OF TRIBOLOGICAL PROPERTIES OF A356-AL2O3 CAST COMPOSITES BY HEAT- TREATMENT

Metal matrix composites have better mechanical and tribological properties compared to the matrix materials. this study presents effect of heat-treatment on hardness and tribological properties of a356 aluminum alloy reinforced with different weight fractions of al_2o_3 particles. metal matrix composites were fabricated by stir casting method. the sliding wear test was carried using pin-on-disc apparatus at a constant sliding speed of 1m/s and load of 30 n. wear resistance of a356 alloy and its composites was improved after heat treatment with improving ratio between 14- 17.3% as compared to as cast conditions. the heat treated test specimens also resulted in marked improvements in hardness as compared with these materials in the as-cast condition.