Mg-10Gd-4.8Y-0.6Zr镁合金热变形行为与加工图

肖宏超^{1, 2}，刘楚明^{1, 2}，徐 璐^{1, 2}，王 霄^{1, 2}，万迎春^{1, 2}

(1. 中南大学 材料科学与工程学院，长沙 410083；
2. 中南大学 有色金属材料科学与工程教育部重点实验室，长沙 410083)

摘 要：在Gleeble-1500热/力模拟机上，对Mg-10Gd-4.8Y-0.6Zr镁合金进行高温压缩试验，压缩时设定应变速率范围为0.001~1 s^-1，温度范围为623~773 K，最大真应变为1.3；研究该合金高温变形时流变应力与应变速率、变形温度之间的关系及变形过程中的微观组织演化；计算塑性变形表观激活能及相应的应力指数；建立该合金的加工图。结果表明：在该合金的加工图中，功率耗散系数η随应变速率的降低及温度的升高而不断增加，失稳区域随应变量的增加而扩大；综合得出该合金的最佳实际变形工艺为温度723~773 K、应变速率0.1~1 s^-1。

关键词：Mg-10Gd-4.8Y-0.6Zr；高温压缩；加工图；变形工艺参数

Deformation behavior and processing map of Mg-10Gd-4.8Y-0.6Zr magnesium alloy

XIAO Hong-chao^{1, 2}, LIU Chu-ming^{1, 2}, XU Lu^{1, 2}, WANG Xiao^{1, 2}, WAN Ying-chun^{1, 2}

(1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Key Laboratory of Nonferrous Metal Materials Science and Engineering, Ministry of Education, <)

Abstract:The processing parameters of Mg-10Gd-4.8Y-0.6Zr magnesium alloy were investigated. The tests were carried out in the strain rate range of 0.001-1 s^-1 and temperature range of 623-773 K, and with the maximum true strain of 1.3 on hot-simulation machine Gleeble-1500. The relationships among the flow stress, the strain rate and the temperature as well as microstructure evolution were investigated. The apparent activation energy during plastic deformation and corresponding stress index were calculated, the processing maps were drawn. The test reveals that the efficiency of power dissipation increases with the increase of temperature and the decline of strain rate, and the instability region expands due to the rise of the temperature in processing maps. Optimal processing parameters were the temperature range of 723-773 K and the strain rate range of 0.1-1 s^-1.

Key words:Mg-10Gd-4.8Y-0.6Zr; hot compression; processing maps; processing parameters