Aging influence on the shape memory effects and superelasticity in titanium-nickel single crystals

On the Ti-50.8%Ni, Ti-S51%Ni and Ti-51.3%Ni (at.%) single crystals, the investigations of the shape memory effects (SME) and superelasticity (SE) have been carried out in order to find out the dependence on a size and a volume fraction of the Ti3Ni4 dispersive particles, a crystal orientation and a sign of applied stress. It is shown, that in crystals without particles the strong dependence of SME on an orientation and a sign of applied stress takes place and SE is not observed. Precipitation of the coherent particles of Ti3N4 of 50-100 nm in size leads to the reduction of SME, weakening of orientation dependence of sigma(cr) in interval of stress-induced martensitic transformations (MT).