Compressive property and energy absorption characteristic of interconnected porous Mg-Zn-Y alloys with adjusting Y addition

In this study, interconnected porous Mg-2Zn-xY alloys with different phase compositions were prepared by various Y additions (x = 0.4, 3, and 6 wt. %) to adjust the compressive properties and energy absorption characteristics. Several characterization methods were then applied to identify the microstructure of the porous Mg-Zn-Y and describe the details of the second phase. Compressive tests were performed at room temperature (RT), 200°C, and 300°C to study the impact of the Y addition and testing temperature on the compressive properties of the porous Mg-Zn-Y. The experimental results showed that a high Y content promotes a microstructure refinement and increases the volume fraction of the second phase. When the Y content increases, different Mg-Zn-Y ternary phases appear: I-phase (Mg3Zn6Y), W-phase (Mg3Zn3Y2), and LPSO phase (Mg12ZnY). When the Y content ranges between 0.4% and 6%, the compressive strength increases from 6.30 MPa to 9.23 MPa, and the energy absorption capacity increases from 7.33 MJ/m3 to 10.97 MJ/m3 at RT, which is mainly attributed to the phase composition and volume fraction of the second phase. However, the average energy absorption efficiency is independent of the Y content. In addition, the compressive deformation behaviors of the porous Mg-Zn-Y are altered by the testing temperature. The compressive strength and energy absorption capacity of the porous Mg-Zn-Y decrease due to the softening effect of the high temperature on the struts. The deformation behaviors at different temperatures are finally observed to reflect the failure mechanisms of the struts.