Effect of Particle Size and Weight Percent of SiC Particles on Microstructure and Hardness of A356-SiC Composites Produced by Semi-Solid Stir Casting

摘要

This research investigates the effects of particle size and weight percent on the hardness of A356 matrix composite reinforced with SiC particulates produced by semi-solid stir casting. The particle sizes of the reinforcing phase were in the form of 37 and 100 μm SiC powders with loading content of 5, 10, 15 and 20 percent by weight. A356 alloy was melted and SiC powder was then gradually added into the continuously stirred slurry to promote uniform distribution of the particulates. It has been found that in the as cast condition, the average hardness values of A356 reinforced with different amounts of 37μm SiC, increase as expected with increasing amounts of particulates. A356 reinforced with 100 μm 10 wt% SiC, followed by T6 treatment, exhibited the highest percentage of hardness increment.