Through a series of experiments with preforms which had random oriented fiber distribution, preform deformation and the tensile strength of metal matrix composites were investigated. Experimental data are presented for injection of aluminum-alloy melts into preforms which are composed of δ-alumina short fiber of SAFFIL with a silica binder. The composites materials used in this study were Al2024 and AC4C. Processing parameters considered in this study were preform temperature, applied pressure, delay time and fiber length. The effects of processing parameters on microstructures of metal matrix composites, SEM micrographs and optical micrographs were also examined.