Compressive properties and energy absorption characteristics of open-cell Mg–Y–Er–Zn foams at different temperatures

The compressive properties of magnesium foam need to be improved for its application in the automobile and aerospace fields. In this study, mixed rare earth (RE) elements, i.e., Y and Er, were added to fabricate the Mg-6Y-4Er-2Zn-0.5Zr foam. Through a series of characterization experiments, the macro-morphology, phase composition, and microstructure of the foam were systematically studied. The compressive strength, energy absorption characteristic, deformation behavior, and failure mode at different temperatures are comparatively investigated. The experimental results show that the long-period stacking ordered (LPSO) phase (Mg12REZn) in the foam strut is 18R structure. The compressive strength and energy absorption capacity of the foam depend on the relative density. In addition, as the temperature increases from room temperature (RT) to 300 °C, the compressive strength and energy absorption capacity are reduced. The failure mode of the foam strut changes from brittle fracture at RT to buckling/bending at 300 °C. These transformations are attributed to the softening of the foam strut and the increasing plasticity under high temperature (HT).