Acta Metallurgica Sinica (English Letters) ›› 2021, Vol. 34 ›› Issue (5): 606-616.DOI: 10.1007/s40195-020-01163-4

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Effect of Zener-Hollomon Parameter on High-Temperature Deformation Behaviors of Mg-6Zn-1.5Y-0.5Ce-0.4Zr Alloy

Bo Wu1, Jianbo Li1,2(), Lizi Liu3, Xianhua Chen1(), Jun Tan1, Jiangfeng Song1, Muhammad Rashad4, Fusheng Pan1   

  1. 1School of Materials Science and Engineering, Chongqing University, Chongqing 400044, China
    2International Joint Laboratory for Light Alloys (MOE), School of Materials Science and Engineering, Chongqing University, Chongqing 400044, China
    3Chongqing Light Alloy Materials and Processing Engineering Technology Research Center, Chongqing Three Gorges University, Chongqing 404130, China
    4School of Materials Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, China
  • Received:2020-07-17 Revised:2020-09-20 Accepted:2020-09-21 Online:2021-05-10 Published:2021-04-30
  • Contact: Jianbo Li,Xianhua Chen
  • About author:Xianhua Chen, xhchen@cqu.edu.cn
    Jianbo Li, lijianbo1202@cqu.edu.cn;

Abstract:

High-temperature compressive deformation behaviors of Mg-6Zn-1.5Y-0.5Ce-0.4Zr alloy were investigated at temperatures and strain rates ranging from 523 to 673 K and from 0.001 to 1 s-1, respectively. The studied alloy was mainly composed of α-Mg, Mg3Zn6Y (I phase), Mg-Zn-Ce and Mg3Zn3Y2 (W phase). The constitutive equation of Mg alloy was obtained, and the apparent activation energy (Q) was determined as 200.44 kJ/mol, indicating that rare earth phase increases the difficulty of deformation. The work hardening involves three stages: (1) linear hardening stage; (2) strain hardening stage; and (3) softening and steady-state stage. During these three stages, the dislocation aggregation and tangling, dynamic recovery and recrystallization occur sequentially. To characterize the dynamic recrystallization (DRX) volume fraction, the DRX kinetics was investigated using the Avrami-type equation. The deformation mechanism of magnesium alloy under different Zener-Hollomon parameter (Z) value conditions was also studied. At high Z values and intermediate conditions, dislocations rapidly generate and pile up in the alloy. Recrystallization is hardly seen at this time. At low Z condition, the DRX occurs in the alloy.

Key words: Mg-6Zn-1.5Y-0.5Ce-0.4Zr alloys, Work hardening, Dynamic recrystallization, Zener-Hollomon (Z) parameter