Effect of semi solid processing on the microstructure and mechanical properties of aluminum matrix composites

Metal Matrix Composites (MMC) have not been used as extensively as forecast for a variety of reasons. One is the extreme difficulty of machining and grinding MMCs because of the hard second phase. Semi Solid Metalworking (SSM) offers the potential to form these materials into very complex parts (net shape) while maintaining a homogeneous distribution of the hard second phase within the part. This paper will provide an overview of SSM processing of various aluminum matrix composites, including aluminum A356 + SiB6, 6092 + SiC and 6061 + Al2O3. In addition, the effect of SSM on microstructure and mechanical properties and will also be presented. This work was conducted by the National Center for Excellence in Metalworking Technology operated by Concurrent Technologies Corporation under contract No. N00140-92-C-BC49 to the U.S. Navy as part of the U.S. Navy Manufacturing Technology Program.