MICROSTRUCTURE PROPERTY RELATIONSHIPS OF INSITU REACTED TIC/AL-CU METAL MATRIX COMPOSITES

A novel technique was utilized for the fabrication of in situ titanium carbide reinforced aluminum alloy metal matrix composites. The reacted, cast, extruded and heat-treated samples exhibited a homogeneous distribution of fine (0.1-3-mu-m) TiC platelets in a fine-grained recrystallized Al-4.5 wt. % Cu matrix. Elevated temperature tensile testing indicated that the composite retains its room temperature strengths up to 250-degrees-C and compared favorably with composites fabricated by more complex and costly processes. When compared with Al-4.5 wt. % Cu alloy processed similarly but without the TiC reinforcement, the additions of TiC resulted in a yield strength and tensile strength increase of 130% and 65% respectively. Fractographic analysis indicated ductile failure, although the ductility and strength were limited by the presence of coarse titanium aluminides (Al3Ti).