SOLIDIFICATION MICROSTRUCTURES OF ALSI7MG-SIC PARTICULATE COMPOSITE

The effect of size and volume percentage reinforcement on the particle distribution in an AlSi7Mg alloy reinforced with SiC have been studie d by unidirectional solidification experiments. Three different partic le sizes have been studied (9, 13 and 23 mu m) and with reinforcement from 0-20 vol.%. The results shows that the homogeneity of the particl e distribution is mainly influenced by the solidification rate and the SiC size. A nearly uniform particle distribution can be obtained when the dendrite cell size is equal to qr smaller than the particle diame ter.