Hot compressive deformation of TC4-DT titanium alloy was carried out with the hot-simulation machine of Gleeble-3500 over the range of deformation temperature from 830℃ to 1000℃ , strain rate from 0. 01s-1 to 10s-1 , and the deformation from 40% to 70% . The deformation behavior and microstructure have been analyzed; meanwhile the constitutive model has been set up. The results reveal that TC4-DT alloy deforms at temperatures below 950℃ when the stress softening phenomenon is very obvious, the deformation mechanisms and deformation activation energy are different from the deformation mechanism above the temperture of 950℃. When the alloy deforms at temperatures above 950℃ , low strain rates ( such ass - 0. 01 s-1 ) contribute to the occurrence of dynamic recrystallization behavior, while at higher strain rates( such ass = 10s '), only the phenomenon of dynamicrecovery generally occurs. The dynamic recrystallization is inhibited.%利用Gleeble-3500型热模拟实验机,研究了TC4-DT损伤容限型钛合金在温度850℃ ～ 1000℃、应变速率0.01～ 10s-1、变形程度为40％ ～ 70％条件下的热变形行为,分析了该合金的流变应力行为及微观组织演变规律,并建立了本构关系模型.研究结果表明,TC4-DT合金在950℃以下的较低温度变形时应力软化现象非常明显,变形机制和热变形激活能不同于950℃以上的较高温度变形机制；在950℃以上高温度变形时,低应变速率(如(ε)=0.01s-1)促进了动态再结晶行为的发生,而在较高的应变速率(如(ε)=10s-1)时,一般只发生动态回复现象,动态再结晶行为受抑制.
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