作　　者： ; ; ; ; ;

机构地区： 中南大学材料科学与工程学院

出　　处： 《中国稀土学报》 2008年第2期182-187,共6页

摘　　要： 采用GLEEBLE-1500热模拟机对Mg-10．2Gd-0．8Se-1．7Mn合金在温度为573～773K、应变速率为0．001～1s^-1、最大变形程度为60％的条件下，进行高温压缩模拟实验研究。分析了合金流变应力和应变速率及变形温度之间的关系，计算了高温变形时的变形激活能和应力指数，为选择这种合金的热变形加工条件提供实验依据。采用金相显微镜分析了合金在不同温度下压缩变形的组织演变。结果表明：合金的稳态流变应力随应变速率的增大而增大，在恒定应变速率的条件下，合金的真应力随温度的升高而降低；合金的变形激活能随着变形温度的升高而增大，特别是在723K时迅速增大。合金在变形过程中发生了不同程度的动态再结晶，变形温度和变形速率对合金再结晶组织有明显的影响。根据实验分析，合金的热加工宜在673～723K范围内进行。 Hot compressive testing of Mg-10. 2Gd-0.8Sc-1.7Mn alloy was performed on a Gleeble-1500 thermal simulator at strain rates varying from 0. 001 to 1 s^1 in the deformation temperature range of 573 - 773 K when the maximum deformation degree was 60%. The relationships between rheology stress and deformation temperature as well as strain rate were analyzed. The deformation activation energy and stress exponent were calculated. Microstructures of the alloy samples deformed at different conditions were examined. The results indicated that the rheology stress became higherwith increase of strain rate at constant temperature, and the theology stress became lower with increase of deformation temperature at constant strain rate. The deformation activation energy became higher with increase of deformation temperature, and became much higher at 723 K. All the samples exhibited different degrees of recrystallization. Deformation temperature and strain rate had great effects on microstructure of the alloy. According to the experiments and analysis, the temperature range for hot deformation of the alloy was suggested to be 673 - 723 K.

关 键 词： 合金 热塑性变形 流变应力 变形激活能 显微组织 稀土

领　　域： [金属学及工艺] [一般工业技术] [金属学及工艺]