TC11钛合金的流变行为及其半经验本构模型  

Flow behavior and semi-empirical constitutive model of TC11 titanium alloy

作　　者：杨艳慧[1] 边丽虹[2] 刘东[1] 刘国伟[1] 郑勇[1] 

机构地区：[1]西北工业大学材料学院,西安710072 [2]中航工业沈阳黎明航空发动机(集团)有限责任公司,沈阳110043

出　　处：《中国科技论文》2015年第22期2648-2652,共5页China Sciencepaper

基　　金：高等学校博士学科点专项科研基金资助项目(20126102120022);西北工业大学基础研究基金资助项目(JC201207)

摘　　要：为了更为精确地预测TC11钛合金热变形过程的流变行为,提高TC11钛合金构件的质量,研究建立TC11钛合金半经验本构模型。通过在880~1 020℃的加热试验,建立TC11钛合金加热温度与β相体积分数的关系。通过热压缩试验研究TC11钛合金在温度为880~1 020℃和应变速率为0.01~10s^(-1)条件下的流变行为,建立Arrhenius方程表示的峰值应力本构方程。综合考虑TC11钛合金热变形过程中的软化机制(动态回复和动态再结晶),以及α/β相转变行为和TC11钛合金流变行为的关系,建立了TC11钛合金半经验本构模型:采用分段函数的形式建立动态回复和动态再结晶机制下的本构方程;引入由β相体积分数表示的修正因子,对TC11钛合金本构方程进行修正。结果表明,采用建立的本构模型得到的TC11钛合金流动应力计算结果与试验数据吻合良好,二者在TC11钛合金相变点以上部分的拟合精度达到96%以上。To more accurately predict the flow behavior of TC11 titanium alloy during hot deformation and improve the quality of the alloy component,a semi-empirical constitutive model was proposed and studied.Through the heating tests of TC11 titanium alloy conducted at 880-1 020℃,the relationship between temperature and volume fraction ofβphase was established.Then flow behaviors of TC11 alloy were investigated based on the isothermal compression tests at temperature range of 880-1 020 ℃ and strain rate range of 0.01-10s-（-1）,and the mathematical relation between peak stress and peak strain was formulated using Arrhenius equations.The semi-empirical constitutive model was established by comprehensively considering the softening mechanism（dynamic recovery and recrystallization）of TC11 titanium alloy in hot deformation process and the relationship betweenα/βphase transformation and flow behavior.Piecewise functions were adopted to set up the constitutive equations for dynamic recovery and recrystallization.And the constitutive equations were validated by introducing the validation index expressed by volume fraction ofβphase.Comparison with test results are in good agreement,and the fitting precision above phase transformation temperature is more than 96%.

关 键 词：TC11钛合金 流变行为 本构模型 动态回复 动态再结晶 

分 类 号：TG146.23[一般工业技术—材料科学与工程]