Rapid Solidification Processing of Discontinuously-Reinforced Metal Matrix Composites

Abstract

High strength, high stiffness, high performance and lightweight structural materials in the form of discontinuously reinforced metal- matrix composites provide attractive combinations of microstructure and mechanical properties through the use of rapid solidification technology. Hybrid materials based on metallic and intermetallic matrices have combined the standard alloys of metals with a wide variety of discontinuous reinforcements such as particulates, whiskers and chopped fibers of ceramic materials. In this paper, several of the rapid solidification techniques for the processing of discontinuously-reinforced metal matrix composites are highlighted and the salient features of each technique are presented and discussed. The variables involved with each processing technique are elucidated. Several spray processing techniques have engendered considerable technological interest, and a few key spray-based methods are examined and discussed. These include spray atomization and deposition processing, low pressure plasma deposition, modified gas welding and the high velocity oxyfuel thermal spraying technique.