The compressive deformation and impact response of a magnesium alloy: influence of reinforcement

Reinforcement of magnesium alloys with ceramic particulates has engineered a new family of materials that are marketed under the trade name metal matrix composites. In this paper is reported the results of a study aimed at understanding the role of particulate reinforcements on compressive deformation and impact response of a magnesium alloy discontinuously-reinforced with silicon carbide (SiC) particulates. An increase in carbide particulate reinforcement content in the magnesium alloy metal matrix was observed to have only a marginal influence on compressive strength and impact energy absorption when compared to the unreinforced counterpart. Microcracking in the metal matrix coupled with failure of the reinforcing SiC particulates both independently dispersed and in clusters dominated the fracture sequence at the microscopic level. The mechanical response of this composite material is discussed in light of the interactive influences of intrinsic microstructural effects, deformation characteristics of the composite constituents, nature of loading and local stress state.