Advances in Low-Temperature (<0.25Tm) Creep Behavior of Single and Two-Phase Titanium Alloys

Not too long ago, the authors found that twinning can be a very slow process (i.e. many orders of magnitude lower than the speed of sound) and contribute to low-temperature (<0.25Tm) creep deformation behavior in single-phase HCP titanium alloys. Since then, it has been shown that this time-dependent twinning behavior can also be found in BCC titanium alloys. Furthermore, the time-dependent twinning was also found to play a significant role in the two-phase α + β titanium alloys. The extent of twinning and its contribution to creep behavior was found to depend on the grain size in the single-phase titanium alloys. In regard to single-phase beta alloys, the stability of the beta-phase was also found to play a significant role in twinning behavior. With respect to the two-phase α + β titanium alloys, twinning was found to depend on the morphology and volume fraction of the phases and stability of the beta phase. These developments are reviewed and the ramifications in regard to the design and selection of titanium alloys for various applications are presented