Deformation Mechanism and Constitutive Consideration for Ti-5Al-5Mo-5V-3Cr-1Zr Alloy Compressed at Elevated Temperatures

To investigate hot deformation behavior of a Ti55531 alloy, a series of isothermal compression tests were performed on a Gleeble-3500 simulator at the temperature range of 1033–1153 K and constant strain rates of 0.001–1 s −1 . Based on the experimental flow stress data, processing map and grain morphology, the deformation mechanism map was summarized. In this study, the dominant microstructural mechanism processed near or above β -transus temperature was considered to be deformation characteristic of β phase, where dynamic recovery was in dominant and at mediate strain rate dynamic recrystallization was also observed. Superplasticity was found at 1003–1033 K and 0.001 s −1 , correlating with dislocation glide and grain boundary slide (GBS). Undesirable plastic flow such as flow localization and flow rotation was found at high strain rate of 0.1-1 s −1 and at the entire test temperature range. The optimum working window of this alloy was finally obtained at 1003–1063 K and 1093–1153 K and at 0.001–0.1 s −1 .