The Role of Deformation Twinning on Creep of Titanium Alloys

Normally, deformation twinning is a process that occurs at rates approaching the speed of sound in bulk metals once a critical stress has been reached. However, recently it has been shown that twins grow at speeds many orders of magnitude lower than the speed of sound during room temperature creep of titanium alloys. The net result is that this twinning process can contribute to the low-temperature (less than 0.25*Tm) creep behavior of α, α−β, and β−titanium alloys. For example, α-Ti alloys with small grain size do not extensively deform by twinning and hence show little overall creep strain. These recent developments are reviewed in this paper. This work is funded by the National Science Foundation under Grant Number DMR-0517351.