Solidification Processing of Cast Metal Matrix Composites Over the Last 50 Years and Opportunities for the Future

This paper reviews the progress of solidification processing of cast metal matrix composites over 50 years since their original discovery, which was first published in 1969. Current use of metal matrix composite components in automotives, railways, space, computer hardware, and recreational equipment are presented. Some cast metal matrix composites which are discussed include aluminum reinforced with graphite, silicon carbide, alumina, and fly ash. Several critical issues in solidification processing of metal matrix composites, including nucleation, growth, the effects of reinforcements of fluidity, and the thermo-physical properties of the melts on micro-segregation, and particle pushing or engulfment during solidification of the are discussed. Current and future directions and challenges in solidification processing of cast metal matrix composites are presented, including the synthesis of self-lubricating, self-healing, and self-cleaning composites using solidification processing.