MICROSTRUCTURE AND MECHANICAL PROPERTY OF IN-SITU AL-CU TIC COMPOSITES/

An approach named direct reaction synthesis (DRS) has been developed t o fabricate particulate composites with an extremely fine reinforcemen t size. In situ Al matrix composites were fabricated by DRS. Extensive analysis of the composites microstructure using SEM and TEM identify that the reinforcement formed during the DRS process is Ti carbide (Ti C) particle, generally less than 1.0 mu m The reacted, semisolid extru ded samples exhibit a homogeneous distribution of fine TiC particles i n Al-Cu matrix. Mechanical property evaluation of the composites has r evealed a very high tensile strength relative to the matrix alloy. Fra ctographic analysis indicates ductile failure although the ductility a nd strength are limited by the presence of coarse titanium aluminides (Al3Ti).