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

Abstract

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.

Keywords

• Porous magnesium
• Rare earth elements
• Microstructure
• Compressive behavior
• Energy absorption characteristic