Constitutive equations for high temperature flow stress of TC4-DT alloy incorporating strain, strain rate and temperature
Constitutive equations for high temperature flow stress of TC4-DT alloy incorporating strain, strain rate and temperature
复制标题
包含应变、应变速率和温度的TC4-DT合金高温流变应力本构方程
DOI：
10.1016/j.matdes.2013.03.009
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发表时间：
2013-09-01
影响因子：
8.4
通讯作者：
Zhao, Zhanglong
中科院分区：
文献类型：
--
作者：
Peng, Xiaona;Guo, Hongzhen;Zhao, Zhanglong
为了获得精确模拟所需的可靠的本构方程，在Gleeble-1500热模拟机上，对TC 4-DT钛合金在1203-1293 K温度范围内，以15 K为间隔，以0.001 ~ 10 s（-1）为应变速率，进行了等温热压缩实验，研究了TC 4-DT钛合金的高温流变行为。结果表明，在真应变小于0.14时，合金的真应力-应变曲线均表现出先应变硬化后流变软化的特征，在较高的应变速率和较低的温度下表现得尤为明显。通过建立应变多项式拟合的材料常数本构方程，考虑了应变速率和温度对流变行为的影响。在应变速率小于1 s（-1）时，本构方程预测的应力值与实验结果吻合较好。建立了考虑应变、应变速率和温度增量补偿的修正本构方程，该方程可以预测除1293 K/1 s（-1）和10 s（-1）以及1278 K/10 s（-1）外的整个应变速率和温度范围内的流变应力。相关系数（R）和平均绝对相对误差（AARE）分别为99.3%和5.07%，表明修正后的本构方程能够准确、精确地估算TC 4-DT钛合金的流变应力。(C)2013爱思唯尔有限公司保留所有权利。
In order to get a reliable constitutive equation for the precise simulation, high temperature flow behavior of TC4-DT titanium alloy was investigated by conducting isothermal hot compression tests in temperature range of 1203-1293 K at an interval of 15 K and strain rate range from 0.001 to 10 s(-1) on Gleeble-1500 simulator. The results revealed that all the true stress-strain curves showed the characteristics of strain hardening (at the true strain lower than 0.14) followed by flow softening and it was particularly significant at higher strain rates and lower temperatures. The effect of strain rate and temperature incorporating strain on the flow behavior was considered by establishing a constitutive equation with the material constants expressed by a polynomial fitting of strain. The stress values predicted by the constitutive equation demonstrated a well agreement with the experimental results at the strain rates under 1 s(-1). A modified constitutive equation considering the compensation of strain, strain rate and temperature increment was developed and could predict the flow stress over the entire range of strain rates and temperatures except at the conditions of 1293 K at 1 s(-1) and 10 s(-1) and 1278 K at 10 s(-1). The correlation coefficient (R) and average absolute relative error (AARE) were 99.3% and 5.07% respectively, which confirmed that the modified constitutive equation could give an accurate and precise estimate of the flow stress of TC4-DT titanium alloy. (C) 2013 Elsevier Ltd. All rights reserved.