Temperature dependent work hardening in Ti-6Al-4V alloy over large temperature and strain rate ranges: Experiments and constitutive modeling
Temperature dependent work hardening in Ti-6Al-4V alloy over large temperature and strain rate ranges: Experiments and constitutive modeling
复制标题
Ti-6Al-4V 合金在大温度和应变率范围内的温度相关加工硬化：实验和本构建模
DOI：
10.1016/j.matdes.2015.06.048
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发表时间：
2015-10-15
影响因子：
8.4
通讯作者：
Li, Jun
中科院分区：
文献类型：
--
作者：
Chen, Guang;Ren, Chengzu;Li, Jun
通过准静态和动态单轴压缩试验，研究了Ti-6Al-4V合金在较宽应变速率（10（-4）~ 104 s（-1））和温度（20 ~ 900 ℃）范围内的塑性变形行为。讨论了Ti-6Al-4V合金在不同温度下的组织演变。当温度高于500 ℃时，材料产生更高的延展性和成形性，这导致加工硬化率降低。真实应力-应变响应采用JC、修正JC、KHL和修正KHL模型模拟。详细地说，一个温度依赖的加工硬化函数被引入到原来的JC和KHL模型。采用遗传算法优化的方法对Ti 6-Al-4V合金的四种模型参数进行了计算。实验和计算的流动应力之间的平均标准偏差为4%至13%，这验证了模型的准确性。此外，还通过动态（10,000 s（-1））流变应力、动态（7500 s（-1））加工硬化率以及准静态跳跃实验对模型进行了验证。修正的JC模型和修正的KHL模型能够描述Ti-6Al-4V合金在大应变速率和温度范围内的温度相关加工硬化效应。(C)2015爱思唯尔有限公司版权所有。
The plastic deformation behaviors of Ti-6Al-4V alloy over wide ranges of strain rate (from 10(-4) to 104 s(-1)) and temperature (from 20 to 900 degrees C) are investigated by the quasi-static and dynamic uniaxial compression tests. The microstructure evolution of Ti-6Al-4V alloy at different temperatures is discussed. Material generates higher ductility and formability when temperature is higher than 500 degrees C, which leads to the decrease of work hardening rate. The true stress-strain responses are modeled with the JC, modified JC, KHL and modified KHL models. In detail, a temperature dependent work hardening function is introduced into the original JC and KHL models. The parameters of the four models for Ti6-Al-4V alloy are calculated by GA optimization method. The average standard deviations between the experimental and calculated flow stresses range from 4% to 13%, which validates the accuracy of the models. In addition, comparison of flow stresses at dynamic (10,000 s(-1)), the work hardening rates at dynamic (7500 s(-1)), as well as the quasi-static jump experiments were proposed to further validate the models. The modified JC and modified KHL models could characterize the temperature dependent work hardening effect for Ti-6Al-4V alloy over large strain rate and temperature ranges. (C) 2015 Elsevier Ltd. All rights reserved.