Compressive Behavior and Damping Property of Mg Alloy/SiCp 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 SiCp 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 SiCp 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 SiCp content. Meanwhile, the SiCp addition elevates the ideal energy absorption efficiency of the Mg alloy foams, but decreases the total amount of energy absorption. Furthermore, the loss factor beta is essentially independent of temperature below approximately 250 degrees 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 SiCp addition. The improvement is attributed to the increasing interfacial microslip and microplasticity deformation derived from the micro-crack between the SiCp-Mg alloy interfaces.