Effect of Nb content on deformation behavior and shape memory properties of Ti-Nb alloys

Deformation behavior and shape memory properties of Ti-(20, 23) at.% Nb alloys in a single alpha martensite state were investigated. The Ti-20Nb alloy exhibited a higher stress for the reorientation of martensite variants when compared with the Ti-23Nb alloy. The recovery strain due to the shape memory effect in the Ti-20Nb alloy was smaller than that in the Ti-23Nb alloy. Transmission electron microscope (TEM) observation revealed that the reorientation of martensite variants occurred by the deformation of {1 1 1} type land < 2 1 1 > type II twins. The Nb content dependence of the deformation behavior and shape memory properties was discussed considering the magnitude of twinning shear of the twins. (C) 2012 Elsevier B.V. All rights reserved.