Characterization and machinability studies of aluminium Alloy-SiC particle composite

Abstract

Metal matrix composite (MMCs) are next generation materials. MMCs add higher strength and stiffness than the matrix alloy, excellent wear resistance and lower coefficient of thermal expansion (CTE). Additional functionalities can be designed into some MMCs through appropriate selection of constituents. One of the important objectives of metal matrix composites is to develop a material with a judicious combination of toughness and stiffness. It decreases the sensitivity to cracks and flaws and at the same time increases the static and dynamic properties. The reinforcement effect occurs due to the extraordinary high strength of whiskers with diameters below a few micrometers. In general, Metal matrix composites consist of at least two components. One is the metal matrix and the second is reinforcement. In all cases, the matrix is defined as a metal, but a pure metal is rarely used as the matrix. It is generally an alloy. In the productivity of the composite, the matrix and the reinforcement are mixed together. Matrices based on Ag, Al, Cu Mg, Ni and Ti are all commercially produced and used. Discontinuously reinforced (DRA) aluminium (Al) accounts for 69% of the annual MMC production by mass. Reinforcements most often used in commercial applications are Al2O3, B4C, and SiC. The reinforcement of largest commercial volume is SiC by a significant margin, followed by Al2O3 and TiC. Nearly, all MMCs in commercial use rely on discontinuous reinforcements, although applications exist for MMCs with continuous graphite, SiC and Al2O3 fibers. MMCs offer advantages such as light in weight, high stiffness, stability at high temperature and good wear resistance. MMCs find applications in the ground transportation (auto and rail), aerospace, industrial, recreational and infrastructure industries.