The isothermal constant strain rate compression test of the forged TC20 titanium alloy was carried out by using Gleeble-3800 thermal simulator.The change of flow stress at 940～1 030℃and strain rate of 0.001～10 s

-1

was investigated.According to the experimental data

the temperature-increment value under different deformation conditions was calculated

and the features of deformation heat generation were analyzed.Based on the superposition diagram of strain rate sensitivity exponent m contour map and instability map

the influence of thermal deformation parameters on the local flow behavior of the TC20 titanium alloy was analyzed combined with the verification of microstructure observation.The results show that the flow stress of TC20 titanium alloy is decreased with the increase of the deformation temperature and increased with the increase of the strain rate.The temperature-increment caused by the deformation heat effect is increased with the increase of the strain rate and decreased with the increase of the deformation temperature.With deformation at 940～990℃and high strain rate of 0.32～10 s

-1

the alloy is prone to local flow with the deformation temperature decreasing and the strain rate increasing.