流变铸造镁合金AZ31B的热/力模拟

来源期刊:中国有色金属学报2005年第11期

论文作者:张少明 杨必成 樊中云 徐骏 石力开 陈国良

文章页码:1675 - 1681

关键词:镁合金; 流变铸造; 热/力模拟

Key words:magnesium alloy; rheo-casting; hot compressive deformation simulation

摘    要:采用双螺旋流变铸造工艺制备了镁合金AZ31B的棒坯, 利用Gleeble-3000型热/力模拟机研究了流变铸造和普通连铸棒坯在变形温度为250~400 ℃, 变形速率为0.001~5 s-1, 最大变形量为60%时的热压缩变形行为。 分析了材料流变应力与变形量、 变形温度和应变速率之间的关系, 比较了两种不同铸造工艺对热塑性变形行为的影响。 结果表明: 流变铸造坯料在变形过程中的形变均匀性明显优于普通铸造的, 因此不需预处理即可直接进行塑性成型; 350 ℃以上热变形流变铸造坯料的变形抗力明显小于普通铸造坯料的; 流变铸造使AZ31B合金的塑性加工性能得到改善; 产生这种差别的主要原因是普通铸造坯料组织为粗大树枝晶, 而流变铸造坯料组织为细小等轴晶。

Abstract: The billet of magnesium alloy AZ31B was prepared by the method of twin-screw rheo-casting and normal casting. The hot compression of these two kinds of samples at 250-400 ℃ was performed on Gleeble-3000 hot simulator with the strain rates of 0.001-5 s-1, and the maximum deformation of 60%. The relationship among the stress, deformation temperature and strain rate were analyzed and compared. The results show that the deformation of rheo-casting billet is more uniform than that of the normal casting in the compression process, so the rheo-cast billet can be hot deformed directly. The maximum stress of rheo-casting is less than that of the normal casting at above 350 ℃, which means that the billet made by rheo-casting can be deformed easier than normal casting. The reason of the difference is that the microstructure of rheo-casting is composed of uniform, tiny and equal-axial grains; while the microstructure of normal casting is coarse dendrite.

基金信息:国家高技术研究发展计划资助项目

有色金属在线官网  |   会议  |   在线投稿  |   购买纸书  |   科技图书馆

中南大学出版社 技术支持 版权声明   电话:0731-88830515 88830516   传真:0731-88710482   Email:administrator@cnnmol.com

互联网出版许可证:(署)网出证(京)字第342号   京ICP备17050991号-6      京公网安备11010802042557号