Solidification science in cast MMCs: The influence of Merton Flemings

The solidification science of cast metal-matrix composites(MMC) evolved as a subset of the broad field of solidification of monolithic alloys pioneere d by Merton Flemings and his students. As a result of advances in solidific ation, the cast MMC field has evolved from its early incarnation-employing empirical research to engineer novel materials using versatile and cost-eff ective casting techniques-to using solidification-science-based approaches to tailor advanced materials for application-spec flc needs. The current an d emerging applications of cast MMCs in a variety of automotive, aerospace, electronic packaging, and consumer-good industries exemplify the maturity of the field and the materials. Innovations in composite-forming techniques and efforts at wider industrial acceptance of MMCs will undoubtedly contin ue. However, the scientific principles underlying the solidification micros tructure evolution that governs the composite properties have become well e stablished, to a great extent, due to Flemings' early, pioneering work on m onolithic alloys and some of his more recent studies on solidification of r einforced metals. This paper reviews some aspects of solidification of disc ontinuously reinforced cast metals that owe their current understanding to Flemings' contributions, in particular, the scientific understanding of mac ro- and microsegregation,fluidity and rheology of multiphase slurries, and stir-casting, send-solid casting, and preform infiltration. Current researc h to develop and test prototype components made from cast composites, inclu ding Al-flyash, Cu-graphite, Al-graphite, Al-alumina, and SiC-Al, is also p resented, along with directions for future research.