Mg-8Gd-3Y-0.5Zr耐热镁合金的热压缩变形行为  

Hot Compression Deformation Behavior of Mg-8Gd-3Y-0.5Zr Magnesium Alloy

作　　者：张志高[1] 夏长清[1] 乔翔[1] 彭小敏[1] 刘莹颖[1] 

机构地区：[1]中南大学有色金属材料科学与工程教育部重点实验室,湖南长沙410083

出　　处：《矿冶工程》2009年第5期105-108,共4页Mining and Metallurgical Engineering

摘　　要：对Mg-8Gd-3Y-0．5Zr（质量分数，％）稀土镁合金在温度为250～450℃、应变速率为0．001～0．1s^-1、最大变形程度为50％的条件下，进行了恒应变速率高温压缩模拟实验研究，分析了实验合金高温变形时流变应力与应变速率及变形温度之间的关系以及组织变化，计算了塑性变形表观激活能及相应的应力指数，结果表明：合金的稳态流变应力随应变速率的增大而增大，在恒应变速率条件下，合金的真应力水平随温度的升高而降低；在给定的变形条件下，计算得出的塑性变形表观激活能和应力指数分别为220kJ／mol和5．6。根据实验分析，合金的热加工宜在350℃左右进行。Simulation experiments of constant-strain-rate hot-compression of Mg-8Gd-3Y-0.5Zr （mass fraction, % ） alloy were carried out at temperatures of 250 -450 ℃ and strain rates of 0. 001 -0.1 s^-1 and a maximum strain of 50%. The relations between flow stress and strain rate and deformation temperature and the microstructures of the tested alloy were studied during hot compression. The apparent deformation activation energy and corresponding stress exponent under hot compression were evaluated quantitatively. The results showed that the steady flow stress increased with the increase of strain rate, while the true stress decreased with the increase of deformation temperature at a constant strain rate. The apparent activation energy and stress exponent calculated under given deformation conditions were 220 kJ/mol and 5.6, respectively. The temperature about 350 ℃ is suggested for hot deformation of this alloy.

关 键 词：MG-GD-Y-ZR 热压缩变形 变形激活能 

分 类 号：TG146.4[一般工业技术—材料科学与工程]