The isothermal constant strain rate compression tests of TA15 titanium alloy with Widmanstatten and basketweave microstructure were carried out by THERMECMASTOR-Z hot working simulator testing machine in the range of 750℃

9

50℃ and strain rate range of 0.001s-1

1

0s-1 in alpha and beta phase Zone.Effect of original structure on plastic flow behavior were appraoched.The results indicate that the stress-strain curves of TA15 titanium alloy are characterized by strain-softening types.The flow softening resulted from the spheroidization of lamellar alpha phase is increased with decreasing in deformation temperature and increasing in strain rate.The degree of flow softening of basketweave microstructure is greater than that of Widmanstatten microstructure at the same hot deformation parameter

which is attributed to the different spheroidization percentage of alpha phase caused by different hot deformation activation energy.