The quasi-static, cyclic fatigue and final fracture behavior of a magnesium alloy metal-matrix composite

In this paper the results of a study to understand the role of composite microstructure on quasi-static, cyclic fatigue, deformation and fracture behavior of magnesium alloy Z6 discontinuously reinforced with silicon carbide (SiC) particulates are presented. Quasi-static fracture of the composite was dominated by cracking of the reinforcing particulates present in the magnesium alloy metal matrix. Final fracture occurred as a result of crack propagation through the alloy matrix between particulate clusters. The composite specimens were cyclically deformed over a range of stress amplitudes. The stress amplitude-fatigue life response was found to degrade with an increase in test temperature. Influence of test temperature on quasi-static and cyclic response and final fracture behavior of the composite is discussed in light of the concurrent and mutually interactive influences of composite microstructural effects, deformation characteristics of constituents of the composite material, magnitude of cyclic stress amplitude and fatigue life.