The thermal deformation behavior and microstructure evolution of the low-density Nb-Ti-Al-Mo-W-Zr alloy were investigated in detail by the isothermal hot compression test with the deformation temperature of 900～1 100 ℃ and strain rate of 0.01～10 s

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on Gleeble-3800 thermal simulation machine. The results indicate that the flow curves of the alloy are characterized by dynamic recrystallization at low strain rate and high deformation temperature

and dynamic recovery at high strain rate and low deformation temperature

respectively. The flow stress is decreased with the increase of deformation temperature or the decrease of strain rate. The deformation behavior at high temperature can be expressed by the hyperbolic sine function constitutive equation

where the average deformation activation energy is 412.37 kJ/mol. In addition

the significant effect of deformation conditions on the microstructure can also be observed. When the temperature is constant

the dynamic recrystallization region becomes larger with the decrease of strain rate

and when the strain rate is constant

the dynamic recovery is gradually transferred into the dynamic recrystallization as the temperature increases.