Microwave synthesis and characterization of metastable (Al/Ti) and hybrid (Al/Ti plus SiC) composites

Two-directional microwave assisted rapid sintering was carried out to fabricate Al/Ti metastable composites and Al/(Ti + SiC) hybrid composites. The length scale of Ti was in microns (20 mu m) and of SiC in nanometers (50 nm). Microstructural characterization revealed uniform distribution of Ti particulates and SiC nanoparticulates in the Al matrix, relatively low amount of porosity and good matrix-reinforcement interfacial integrity. Coefficient of thermal expansion of the Al matrix reduced due to the presence of Ti and Ti + SiC reinforcements. The results revealed that addition of SiC nanoparticulates to Al-Ti formulations assisted in increasing microhardness, macrohardness, Al-Ti interfacial hardness, 0.2% YS and UTS while the ductility was marginally affected. Particular emphasis was placed to study the feasibility of using hybrid reinforcements in the Al matrix synthesized by using microwaves. (c) 2006 Elsevier B.V. All rights reserved.