Constitutive Equation and Hot Processing Map of Mg-16Al Magnesium Alloy Bars

Materials

Zongwen Ma¹  Zhenxiong Wei¹  Zhongjun Wang¹  Weijuan Li¹  Kuijun Fu²  Jiaji Wang²  Fengya Hu² 

[1] School of Materials and Metallurgy, University of Science and Technology Liaoning, Anshan 114051, China;State Key Laboratory of Metal Material for Marine Equipment and Application, Ansteel Group Corporation, Anshan 114009, China;

关键词: magnesium alloy;    Mg-16Al;    hot deformation;    constitutive equation;    processing maps;   

DOI  :  10.3390/ma13143107

来源: DOAJ

【 摘 要 】

A Gleeble-2000D thermal simulation machine was used to investigate the high-temperature hot compression deformation of an extruded Mg-16Al magnesium alloy under various strain rates (0.0001–0.1 s⁻¹) and temperatures (523–673 K). Combined with the strain compensation Arrhenius equation and the Zener–Hollomon (Z) parameter, the constitutive equation of the alloy was constructed. The average deformation activation energy, Q, was 144 KJ/mol, and the strain hardening index (n ≈ 3) under different strain variables indicated that the thermal deformation mechanism was controlled by dislocation slip. The Mg-16Al alloy predicted by the Sellars model was characterized by a small dynamic recrystallization (DRX) critical strain, indicating that Mg₁₇Al₁₂ particles precipitated during the compression deformation promoted the nucleation of DRX. Hot processing maps of the alloy were established based on the dynamic material model. These maps indicated that the high Al content, precipitation of numerous Mg₁₇Al₁₂ phases, and generation of microcracks at low temperature and low strain rate led to an unstable flow of the alloy. The range of suitable hot working parameters of the experimental alloy was relatively small, i.e., the temperature range was 633–673 K, and the strain rate range was 0.001–0.1 s⁻¹.

【 授权许可】

Unknown