The kinetics of dynamic and static softening during multistage hot deformation of 7150 aluminum alloy
The kinetics of dynamic and static softening during multistage hot deformation of 7150 aluminum alloy
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DOI：
10.1016/j.msea.2012.05.039
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发表时间：
2012-08-30
期刊：
影响因子：
6.4
通讯作者：
Chen, Jianghua
中科院分区：
文献类型：
--
作者：
Jiang, Fulin;Zhang, Hui;Chen, Jianghua
在Gleeble-1500系统上进行了等温连续和间断热压缩试验，温度分别为300℃和400℃，应变速率分别为0.01 s（-1）和0.1 s（-1）。利用流动曲线和相对软化速率研究了7150铝合金在多阶段热变形过程中的动态和静态软化动力学。结果表明：7150铝合金在热变形过程中流动曲线出现峰值，并有一定的工作软化；流动应力随应变速率的增大和温度的降低而增大，流动软化程度减小。静态软化随应变速率、变形温度和延迟时间的增加而增加。当温度为400℃时，静态软化曲线呈典型的s型曲线，而当温度降至300℃时，静态软化曲线呈平稳状态，400℃时，静态软化曲线超过100%。基于Johnson-Mehl-Avrami-Kolmogorov模型，导出了7150铝合金的静态再结晶经验模型，再结晶活化能为219.17 kJ/mol。(C) 2012 Elsevier B.V.版权所有
Isothermal continuous and interrupted hot compression tests have been carried out on Gleeble-1500 system at temperatures of 300 degrees C and 400 degrees C, strain rates of 0.01 s(-1) and 0.1 s(-1), respectively. The dynamic and static softening kinetics of 7150 aluminum alloy during multistage hot deformation were investigated by means of flow curves and relative softening rates. The results show that the flow curve exhibits a peak and some work softening during hot deformation of 7150 aluminum alloy. The flow stress increased with increasing strain rate and decreasing temperature while the flow softening decreased. The static softening increased with increasing strain rate, deformation temperature and delay time. The static softening curves appeared as a typical sigmoidal shape of the type at temperature of 400 degrees C, while plateaus were observed when temperature decreased to 300 degrees C. The appearance of static softening at 400 C exceeding 100% was observed. An empirical static recrystallization model based on Johnson-Mehl-Avrami-Kolmogorov model with the recrystallization activation energy of 219.17 kJ/mol for 7150 aluminum alloy was derived. (C) 2012 Elsevier B.V. All rights reserved.