An ideal reinforcement for structural composites

Different criteria and accumulated data lead to the conclusion that discontinuously reinforced metal-matrix composites (DR MMCs) will become an engineering material of general use. At the end of 1970s, the automobile and transport industries had a strong interest in and high expectations for DR-MMCs because of their superior specific strength and rigidity when compared with conventional aluminum alloys. After two decades of development, the first DR-MMC application, an engine connecting-rod, is ready to market. Major applications in the automobile industry, such as brake rotors and drive shafts, are now in the later stages of development, and other engineering applications are well advanced. DR-MMC technology is now recognized worldwide, and research groups are able to introduce remarkable applications of these materials to the market. Three main problems must be solved to facilitate the expanding application of DR-MMCs with light-metal-alloy matrices. They are: (1) superior cost performances; (2) active implementation of environmental concerns; (3) improved ductility. The immediate solution of these problems is impossible. However, many researchers and managers firmly believe that solutions will be found if the same amount of energy is devoted to solving these problems as has been expended during the past two decades of DR-MMCs R and D.