(1. 安徽工业大学 材料科学与工程学院,马鞍山 243002;
2. 中国人民解放军海军工程大学 化学与材料系,武汉 430033;
3. 马鞍山钢铁股份有限公司 第四钢轧总厂,马鞍山 243000)
摘 要: 在应变速率为1×10-3~1 s-1、温度为300~450 ℃条件下,采用Gleeble-3500型热模拟机对Mg-1.3Zn-1.7Ca (质量分数,%)镁合金(ZX115)进行单轴热压缩实验;通过分析ZX115镁合金的真应力-真应变曲线,探讨变形温度和应变速率对其流变曲线中峰值应力、峰值应变及Zener-Hollomom参数的影响,建立描述该合金高温压缩变形的本构方程。将本构方程应用于有限元分析软件 DEFORM 3D中,并对ZX115镁合金热压缩过程进行数值模拟,利用后处理程序,分析工件内部的应变速率场、应变场和温度场变化。研究表明:温度越高或应变速率越低时,流变曲线所达到的峰值应力越小,而在相同的应变速率下,峰值应变也随着变形温度的升高而明显减小;ZX115合金热压缩过程具有明显的变形不均匀性,为了合理控制变形后的再结晶晶粒尺寸,可适当降低形变温度和应变速率。
关键字: ZX115镁合金;Ca;热压缩;流变曲线;本构方程
(1. School of Materials Science and Engineering, Anhui University of Technology, Maanshan 243002, China;
2. Department of Chemistry and Materials, Naval University of Engineering, PLA, Wuhan 430033, China;
3. No. 4 Steel Making and Rolling General, Maanshan Iron and Steel Co., Ltd., Maanshan 243000, China)
Abstract:The hot compressions of Mg-1.3Zn-1.7Ca (mass fraction, %)magnesium alloy (ZX115) were carried out on Gleeble-3500 thermal simulator at a strain rate of 1×10-3-1 s-1 and temperature range of 300-450 ℃. Based on the true stress-strain curves of ZX115 magnesium alloy obtained from experiments, the effects of deformation temperatures and strain rates on the peak stress, peak strain and Zener-Hollomon parameter were discussed, and the constitutive equations were established to describe the hot compression of ZX115 magnesium alloy. These constitutive equations were applied into finite element analysis software DEFORM 3D and then the hot compressions of ZX115 magnesium alloy were simulated. The variation and distribution of strain rate, strain and temperature in the compressed workpiece were analyzed by the post-processing procedures. The results show that peak stress decreases with increasing the deformation temperature or decreasing the strain rate, and the peak strain decreases with increasing the temperature under a given strain rate. The hot compressions of ZX115 magnesium alloy exhibits a nonuniform characteristic. In order to control the recrystallized grain size, the deformation temperature and strain rate should be necessarily decreased.
Key words: ZX115 magnesium alloy; Ca; hot compression; flow curve; constitutive equation