The Gleeble-3500 thermal simulation compressor was applied to conduct isothermal and constant strain rate thermal simulation compression tests

and the thermal deformation behavior of TC21 titanium alloy was investigated at deformation temperature of 870～990 ℃ and strain rate of 0.001～10 s

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. The results indicate that at the strain rate of 0.1 s

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the increase of deformation temperature promotes the dynamic recrystallization

and the α phase grains in the microstructure are gradually elongated and broken

refining the grain size. When the deformation temperature is 870 ℃ and the strain rate is 0.01 s

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the α phase grains in the microstructure are finer with more uniformly. Through the analysis and calculation of the thermal simulation experimental data

the deformation activation energy Q of TC21 alloy was obtained

and the flow stress constitutive equation and recrystallization kinetic model under high temperature condition were established. Finally

the error analysis of the recrystallization kinetics model was performed

verifying the accuracy of the model.