Dynamic Compressive Property of Closed-Cell Mg Alloy Composite Foams Reinforced with SiC Particles

The high-strain-rate mechanical response of Mg alloy/SiCp composite foams has received increased attention in recent years due to their light weight and potential to absorb large amounts of energy during deformation. Dynamic compressive properties of closed-cell Mg alloy/SiCp composite foams with different relative densities (0.162, 0.227 and 0.351) and different SiCp additions (0, 4 and 8 wt%) have been investigated using Split-Hopkinson pressure bar. It is shown that peak stress and energy absorption capacity significantly increase as the relative density increases at the range of testing strain rates. Peak stress and energy absorption display strain rate dependence. The peak stress of specimens with 0 wt% and 4 wt% SiC particles additions grows with increasing strain rate. Meanwhile, the increment in the peak stress of specimens with 8 wt% addition is not significant with strain rate increasing. The increase in strain rate increases the energy absorption capacity. The suitable amount of SiC particles addition has great advantages over increasing the peak stress and energy absorption capacity at the high strain rate. The strain-rate-sensitive matrix, cell morphology, morphological defects and gas pressure have an impact on the strain-rate sensitivity of Mg alloy/SiCp composite foams.