Compressive Behavior and Damping Property of Mg Alloy/SiC_p Composite Foams

The Mg alloy composite foams reinforced by SiC particles were fabricated by the melt foaming route. The composite foams exhibit uniform cell structure with a size of 0.6-0.8 mm and SiC_p distribution. The compressive behavior and damping property of the composite foams were emphasized. It is shown that the yield stress and the plateau stress depend on both porosity and SiC_p content of the composite foam, which decrease with the increasing porosity, while sharper fluctuation of flow stress in the plateau region appears under the higher SiC_p content. Meanwhile, the SiC_p addition elevates the ideal energy absorption efficiency of the Mg alloy foams, but decreases the total amount of energy absorption. Furthermore, the loss factor β is essentially independent of temperature below approximately 250 °C, then increases rapidly with the increasing temperature. It is concluded that the composite foams show typical brittle characteristic and better damping property compared to Mg alloy foams for the SiC_p addition. The improvement is attributed to the increasing interfacial microslip and microplasticity deformation derived from the micro-crack between the SiC_p-Mg alloy interfaces.