SHS amidst other new processes for in-situ synthesis of Al-matrix composites: A review

Abstract

The in-situ synthesized Al-matrix composites exhibited better mechanical properties than the composites prepared by ex-situ synthesis. Several in-situ processes for production of carbide-reinforced Al-matrix composites were comparatively discussed. The benefits of SHS process as compared to other insitu techniques are highlighted. The use of halide salts replacing elemental Ti in SHS reactions turned helpful for in-situ generation of nano particles in the Al matrix. The size, shape, and distribution of in-situ prepared reinforcing particles in Al-matrix are uniform and homogeneous. The reinforced surface is compatible with the undoped matrix surface, thus providing strong bonding. The formation of particle clusters and agglomerates can be minimized or eliminated by proper choice of in-situ processing conditions. Also addressed are the problems concerning the formation of Al₃Ti and Al₄C₃ intermetallics as byproducts.