The Gleeble-3800 thermal simulation testing machine was utilized to conduct isothermal constant strain rate compression experiments on SP700 titanium alloy

and the thermal deformation behavior of the alloy at deformation temperature of 700～950 ℃

strain rate of 0.001～1 s

-1

and maximum strain of 0.9 was investigated. The influence law of different deformation process parameters during thermal deformation on microstructure evolution and microhardness of the alloy was analyzed. The results indicate that the deformation temperature and strain rate have a great influence on the peak flow stress

microstructure evolution and microhardness of the alloy. When the strain rate is constant

with the gradual increase of the deformation temperature

the peak flow stress of the alloy is decreased

and α phase is gradually spheroidized

which finally undergoes dynamic recrystallization

while the microhardness is increased firstly and then decreased

and finally increased again. When the deformation temperature is constant

with the gradual increase of the strain rate

the peak flow stress is increased

and the spheroidization rate of α phase is decreased

which finally presents a local flow phenomenon

and the microhardness is firstly increased and then decreased.