THE SIC PARTICULATE DISTRIBUTION IN THE AS-CAST STRIPS OF SICPT/A356 ALUMINIUN MATTRIX COMPOSITES BY THE TWIN ROLL CASTING

The twin roll casting of the SiCp/A356 aluminium matrix composite strips is investigated,with particular attention to the effects of the SiC volume fraction (3%-16%) and the casting speed (0.5-10m/min) on the SiC particulate distribution. A SiC-poor layer is found in the as-cast strips. When a higher casting speed is used,or there is a higher SiC volume fraction in the composites,the particulate-poor layer can be virtually eliminated. The results also show that the rapid solidification process of the twin roll casting can obviously refine aluminium-silicon eutectic structure and improve the SiC distribution in the matrix.