Abstract: The deformation behavio r of the TC6 alloy at hig h temperature has been investigated using tensile tests.By SEM technolog y, the fracture mechanism has been analyzed throug h the morphologies of the failure surface. Theex perimental r esults show that : ① t he increase of defo rmation temperature and the decrease of strain rate ar e propitious to the improvement of the deformation ability of the TC6 alloy; ② the optimal process par ameters ar e the combination of 950℃ and 0. 001s^{- 1}, and the larg est elongation ratio can reach 267%; ③ t he tough fracture is the mainmode during the fracture procedure of the TC6 alloy; ④the fr actur e begins from the inclusions, and with the increment of deformation and the decr ement of str ain rate, it presents the much more tough fracture character istic.

Key words: titanium alloy, superplastic deformation, fracture mechanism, morphologies of failure surface, high temperature tensile