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880～1020℃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880～1020℃和应变速率为0．01～10 s－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 0.01-10 s-1 ,and the mathematical relation between peak stress and peak strain was formulated using Arrhe-nius 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%.
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