Superplastic tensile test of TB8 alloy was carried out with constant strain rate in the electronic universal tensile testing machine at 760

8

80 ℃ and strain rate of 0.000 1

0

.01s

-1

.Flow stress behavior was analyzed

and the superplastic tensile deformation activation energy and corresponding stress exponent were calculated.Stress-strain constitutive model of the TB8 titanium alloy was established.The results show that the flow stress is decreased with the increase of deformation temperature at a constant strain rate

while it is increased with the increase of strain rate at a constant deformation temperature.The maximum elongation of 356% can be obtained with the deformation at 840 ℃ and the strain rate at 10

-4

s

-1

.The superplastic deformation activation energy and the corresponding stress exponent are 251.25kJ/mol and 2.389 5

respectively.