MICROSTRUCTURE AND MECHANICAL PROPERTIES OF AL MATRIX COMPOSITES PRODUCED BY LCCS PROCESS

Three kinds of metal matrix composites(MMCs) were produced in situ by Low Pressure Casting/Combustion Synthesis(LCCS) Process. Near-net-shape trialuminidereinforced composites can be fabricated without cavities. The reaction between Nb powder and molten Aluminum was negligible at the present processing condition. Mechanical properties of Al-matrix composites reinforced by Al3Fe were poor because of the heterogeneous dispersion of reinforcement by coarse Al3Fe. In all composites investigated, good mechanical properties were obtained from Al-matrix composite containing Al3Ti. In this case, it was indicated that wetability between matrix and reinforcement was good. With increasing Al3Ti in MMC, the tensile strength of Al/Al3Ti composites was improved at the expense of their ductility.