摘要
目的建立近β钛合金Ti-6Mo-5V-3Al-2Fe-2Zr(质量分数)的热变形本构方程,绘制热加工图,确定该合金的流变失稳区和适宜加工区,为其在工业生产中热加工工艺参数的制定提供指导。方法在变形温度700~850℃、应变速率0.0005~0.5 s^(-1)、真应变0.7的条件下,对近β钛合金Ti-6Mo-5V-3Al-2Fe-2Zr进行热压缩实验;基于Arrhenius方程建立该合金的热变形本构方程,并对方程进行验证;根据Prasad失稳准则,构建该合金的热加工图。结果该合金的流变应力随着变形温度的升高而减小,随着应变速率的增大而增大;其热变形激活能为226.29 kJ/mol,本构方程为ε=e^(21.1619)[sinh(0.00834σ)]^(3.11068)exp[-226.29/(RT)];通过热变形本构方程得到的峰值应力计算值与实验值平均误差为4.21%。结论建立的热变形本构方程预测了流变应力,描述了该合金的热变形行为;通过叠加合金的能量耗散图和流变失稳图,获得了该合金的热加工图。基于热加工图确定该合金的流变失稳区为变形温度700~755℃与784~850℃、应变速率0.5~0.05 s^(-1),最佳加工区为变形温度836~850℃、应变速率0.0005~0.005 s^(-1)。
The work aims to derive the thermal deformation constitutive equation of the Ti-6Mo-5V-3Al-2Fe-2Zr(wt.%)alloy and prepare the thermal processing map to determine the rheological instability zone and suitable processing zone of the alloy,so as to provide guidance for the formulation of the thermal processing parameters of the alloy during industrial production.Thermal compression experiment was carried out on the Ti-6Mo-5V-3Al-2Fe-2Zr(wt.%)alloy at deformation temperature of 700 to 850℃,strain rate of 0.0005 to 0.5 s^(-1),and total strain of 0.7.Based on Arrhenius equation,the thermal deformation constitutive equation of the alloy was derived and verified.The thermal processing map of the alloy was established based on Prasad instability criterion.The flow stress decreased with the increasing deformation temperature and increased with the increasing strain rate.The thermal deformation activation energy of the alloy was 226.29 k J/mol.The constitutive equation wasε=e^(21.1619)[sinh(0.00834σ)]^(3.11068)exp[-226.29/(RT)].The average error between the calculated peak stress value and the experi-mental value obtained from the thermal deformation constitutive equation was 4.21%.The established thermal deformation constitutive equation predicts the flow stress of the alloy and describes the thermal deformation behavior.The thermal processing map of the alloy is obtained by superposing the energy dissipation diagram and the rheological instability diagram.Based on the thermal processing map,the rheological instability zone of the alloy is determined to have deformation temperature of 700-755℃and 784-850℃and strain rate of 0.5-0.05 s^(-1),while the optimum thermal processing zone has deformation temperature of 836-850℃and strain rate of 0.0005-0.005 s^(-1).
作者
武小茜
赵洪川
岳婷婷
沈儒风
周舸
张浩宇
WU Xiao-xi;ZHAO Hong-chuan;YUE Ting-ting;SHEN Ru-feng;ZHOU Ge;ZHANG Hao-yu(School of Materials Science and Engineering,Shenyang University of Technology,Shenyang 110870,China)
出处
《精密成形工程》
北大核心
2023年第1期34-40,共7页
Journal of Netshape Forming Engineering
基金
国家自然科学基金(52104379)
辽宁省“揭榜挂帅”科技攻关(2021JH1/10400069)
辽宁省大学生创新训练计划(S202110142013)。
关键词
钛合金
热变形
流变应力
本构方程
热加工图
titanium alloy
thermal deformation
flow stress
constitutive equation
thermal processing map
作者简介
武小茜(2001-),女,本科生,主要研究方向为金属材料工程;通讯作者:张浩宇(1987-),男,博士,副教授,主要研究方向为高性能钛合金设计及变形工艺。
