The Gleeble-3500thermal simulator was used to investigate the high temperature flow stress and microstructure of Ti-22Al-24Nb alloy at 900～1 110℃and 0.01～10s

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.The effects of strain rate and deformation temperature on the flow stress and microstructure of Ti-22Al-24Nb alloy were analyzed.The results indicate that the deformation temperature and strain rate have a significant effect on the high temperature flow stress of Ti-22Al-24Nb alloy.The flow stress is decreased with the increase of deformation temperature and increased with the increase of strain rate.When the deformation is performed at a high strain rate（6）ε≥1.0s

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)in theα

2

+B

2

two-phase region

local microstructure plastic flow and adiabatic shear occur in the microstructure of the alloy.In the B

2

single-phase region

when the deformation is carried out at a low strain rate（6）ε≤0.1s

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)

there exists obvious dynamic recrystallization grains.At high strain rates

the original B

2

phase grains are significantly elongated and the grain boundaries are mostly discontinuous.Under the condition of low strain rate（6）ε≤0.1s

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)

the dynamic recrystallization occurs more easily with the increase of deformation temperature.With the deformation temperature higher than 990℃

apparent dynamic recrystallization characteristics begin to appear.Under the high strain rate（6）ε≥1.0s

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)

the grain boundary is blurred

and with the decrease of the deformation temperature

the grain boundary almost disappears

so the alloy is prone to local plastic flow and adiabatic shearing.