Microstructures and Mechanical Properties of Extruded Mg-Ho-Zn Alloys with Different Ho/Zn Ratios

• DOI: 10.1007/s11837-019-03925-7
• Publication Date: 2019-11-26T20:03:17Z
• Authors: Jiaan Liu; Jie Wang; Mengli Yang; Xiaoru Zhang; Chaojie Che; Dongwen Zhou; Yonghua Wang
• Keywords: 0203 mechanical engineering; 02 engineering and technology

The microstructures and mechanical properties of as-extruded Mg-Ho-Zn alloys with various Ho/Zn ratios have been investigated. The grain size is refined with increasing Ho addition. The presence of second phase in the alloys, i.e., long-period stacking ordered (LPSO) phase and W-phase, is dependent on the Ho/Zn ratio. The strength of the alloys decreased as the test temperature was increased. Among the experimental alloys, the alloy containing LPSO-phase exhibited the best comprehensive mechanical properties at both room and high temperatures, due to the high plasticity and good thermal stability of the LPSO-phase. Related mechanisms were analyzed via metallographic and fractographic examination and then discussed. A schematic diagram was established to further reflect the different roles of W-phase and LPSO-phase in the fracture behavior of the alloys.