(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 410012；
3. 中国航天科学和工业集团 防御技术研究试验中心，北京 100854)
摘 要: 采用Geeble-1500热模拟实验机对Mg-6Gd-3Y-0.5Zr合金进行热压缩实验，设定变形温度为623~773 K、变形速率为0.001~1 s-1、最大真应变为0.6，利用指数函数关系计算合金的表观激活能，并建立合金的表观激活能图。根据动态材料模型(DMM)计算该合金的加工图，综合分析合金的表观激活能图、加工图以及m、 、S和 这4个判据得到：在723 K、0.01 s-1以及773 K、0.1 s-1的条件下，该合金能够获得稳定的塑性变形，并确定为该合金的最佳变形工艺。结合表观激活能图、加工图以及m、 、S和 这4个判据，能够更加准确地判断合金塑性失稳的工艺范围。
关键字: Mg-Gd-Y-Zr合金；热压缩；加工图；表观激活能；塑性失稳判据
（1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Key Laboratory of Nonferrous Materials, Ministry of Education, Central South University, Changsha 410012, China;
3. Defense Technology Research and Test Center, China Aerospace Science and Industry Corporation, Beijing 100854, China）
Abstract:The hot compression tests were performed on Mg-6Gd-3Y-0.5Zr alloy at the deformation temperatures of 623-773 K, strain rates of 0.001-1 s-1 and the maximum true strain of 0.6 by using Geeble-1500 test machine. The apparent activate energy was calculated according to exponential function, and the apparent activate energy map was established. The processing map was obtained according to dynamic materials model (DMM). The optimum deformation conditions when the alloy can obtain the stable plastic deformation are obtained at condition of 723 K, 0.01 s-1 and 773 K, 0.1 s-1 by analyzing the apparent activate energy map, processing map and four criteria of m, , S and systematically. A more accurate range of the conditions for instable deformation can be determined by analyzing the apparent activate energy map, processing map and four criteria.
Key words: Mg-Gd-Y-Zr alloy; hot compression; processing map; apparent activate energy; plastic instability criteria
