田伟
,
李红斌
,
郑明月
,
徐树成
兵器材料科学与工程
利用Gleeble3500热模拟试验机进行材料的高速（应变速率大于1 s-1）试验时，由于采用的stroke模式导致速率偏离目标速率以及塑性功转化热在短时间内散发不出去，使试样温度偏离设置温度、材料变形偏离目标变形条件。为构建材料真实变形条件下的本构方程，通过分析速率及温升与应变之间的关系，在传统本构方程的基础上构建了带有速率修正和温度弹跳的本构方程模型。结果表明，修正后的本构方程具有较高的预测精度。
关键词:
热压缩变形
,
本构方程
,
速率修正
,
温度弹跳
B. Z. Bai X.J.Sun and L.Y.Yang 1) Department of Materials Science and Engineering
,
Tsinghua University
,
Beijing 100084
,
China 2) Beijing Research Institute of Mechanical and Electrical Technology
,
Beijing 100083
,
China
金属学报(英文版)
Gleeble1500 thermo-mechanical simulation machine is considered to be the first grade equipment in materials' research. However, it is seldom used in superplastic research. Perhaps this is because its specimen's heating method is not suitable to get large elongation. Elongation is an important parameter to evaluate superplasticity, but some other parameters such as the relationship between stress and strain rate are more important than elongation-it is an essential property to superplasticity. The stress-strain rate relationship can be very easily and very accu- rately got with Gleeble machine than with some other simlar equipment, and the relationship between microstructure and superplastic deformation is more easily examined with Gleeble. Present authors have got some new achievement in anisotropy, heterogeneity of superplastic deformation, and first put forward the regulation of dynamic equilibrium in microstructural evolution during superplastic deformation. All of these have been concluded from the experimental results mainly through Gleeble as well as the microstructural examination.The research work has got the support of National Natural Science Foundation and some international cooperation. Some theoretic and experimental results have been used in the practice of superplastic forming. Obvious effect of reducing cost and improving quality of formed parts has been achieved.
关键词:
thermo-mechanical simulation
,
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