Production of Al-Si-SiCp cast composites by injection of low-energy ball-milled Al-SiCp powder into the melt

Al-7wt%Si-10wt%SiC p composite with uniformly distributed reinforcement particles with the average size of about 3 microns was produced by a special compocasting method in which the reinforcement was injected into the melt in the form of particulate Al-SiC p composite powder instead of SiC p . The effects of the reinforcement addition form, the solid fraction of primary alpha-aluminum particles at pouring, and stirring speed on the incorporation of reinforcement particles into the matrix were investigated. Injection of particulate Al-SiCp composite led to improved incorporation and dispersion and reduced size of SiC p . Casting from the semisolid state significantly improved the incorporation of SiC p into the matrix. The optimal solid fraction of primary alpha-aluminum particles to achieve a reasonable combination of reinforcement incorporation and fluidity of the composite slurry was recognized to be about 0.1. The incorporation of SiC p was improved by increasing the stirring speed up to 500 rpm and then gradually decreased.