基于应变补偿TC4-DT钛合金高温变形本构模型  

Constitutive Model of TC4-DT Titanium Alloy at Elevated Temperature Considering Compensation of Strain

作　　者：刘江林[1] 曾卫东[1] 谢英杰 舒滢 杨建朝 

机构地区：[1]西北工业大学凝固技术国家重点实验室,陕西西安710072 [2]西部钛业有限责任公司,陕西西安710201

出　　处：《稀有金属材料与工程》2015年第11期2742-2746,共5页Rare Metal Materials and Engineering

基　　金：国家重点基础研究发展计划("973")计划(2007CB613807);教育部"新世纪优秀人才支持计划"项目(NCET-07-0696);陕西省科技统筹创新工程计划项目(2012KTZB01-03)

摘　　要：通过TC4-DT钛合金在1181~1341 K,0.01~10 s^(-1)条件下热模拟压缩试验,得到其在不同条件下高温变形真应力-真应变曲线。采用回归分析和多项式拟合建立了应变补偿高温变形本构方程。结果表明:各变形条件下的流变应力曲线均呈现应变硬化和流动软化,低温高应变速率特征更明显。当应变速率低于1 s^(-1)时,预测值与实验值吻合程度较高,相关系数和平均相对误差绝对值分别为0.9952和5.78%,此修正模型可作为TC4-DT钛合金高温变形本构方程。Elevated-temperature flow behavior of TC4-DT titanium alloy was investigated by conducting isothermal hot compression tests at strain rate from 0.01 to 10 s-1 and in the temperature range of 11811341 K on Gleeble-3500 simulator.The Arrhenius constitutive equation considering the strain was established based on the experiment data with the material constants expressed by a polynomial fitting of strain.The results show that all the true stress-strain curves exhibit the characteristics of strain hardening followed by flow softening and it is particularly significant at higher strain rates and lower temperatures.The flow stress values predicted by the developed constitutive model demonstrate a well agreement with the experimental results at the strain rates under 1 s-1.The correlation coefficient（R）and average absolute relative error（AARE） are 0.9952 and 5.78%,respectively,which confirm that the modified constitutive equation could give an accurate and precise estimate of the flow stress of TC4-DT titanium alloy.

关 键 词：TC4-DT钛合金 热变形 应变补偿 本构方程 

分 类 号：TG146.23[一般工业技术—材料科学与工程]