均匀化态Mg-Gd-Y-Zn-Mn合金热变形行为及加工图

Hot deformation behavior and processing maps of as-homogenized Mg-Gd-Y-Zn-Mn alloy

摘要:

通过温度在350℃-500℃，应变速率在0.001/s-1/s的热压缩实验，本文研究了均匀化态Mg-Gd-Y-Zn-Mn合金热变形行为和加工图。采用双曲线模型，建立了本构方程，计算了激活能为260.94kJ/mol。基于动态材料模型，绘制了应变量为0.6,1.2的均与化态Mg-Gd-Y-Zn-Mn合金的加工图，用于研究材料的热成性。应变量1.2加工图显示适合合金加工的两个安全区域：一个是变形温度460℃-500℃，应变速率0.001/s-1/s；另一个是变形温度350℃-500℃，应变速率0.001/s-0.005/s。同时，讨论了相应的微观组织演变，重点关注了该合金中长程堆垛有序相（LPSO）的变相机制。

Abstract:

The hot deformation behavior and processing maps of as-homogenized Mg-Gd-Y-Zn-Mn alloy were investigated by hot compression tests performed at 350-500°C and strain rates ranging from 0.001/ s to 1/ s . The constitutive equation was established using hyperbolic law, and the activation energy of the alloy was calculated to be about 260.94 kJ/mol. Based on the dynamic material model, processing maps of as-homogenized Mg-Gd-Y-Zn-Mn deformed at strain values of 0.6,1.2 were drawn to study the hot workability of the alloy. The processing map developed at a strain of 1.2 shows two safety domains: one occurring at 460–500°C and strain rates ranging from 0.001 /s to 1 /s; the other occurring at 350–500°C, and strain rate ranging from 0.001/s to 0.005/s. The corresponding microstructure evolutions, with particular emphasis on the deformation mechanism of long-period stacking ordered phase (LPSO) in this alloy, were also discussed.