Influence of crystallographic texture and phase composition on the effect of superelasticity of foils from alloys based on Ti — Nb

The results is presented of the analysis of the structure, crystallographic texture and anisotropy of manifestation of the superelasticity effect for foils rolled from forged ingots of Ti-22%Nb-6%Zr, Ti-9%Nb-46%Zr, Ti-22% Nb-(1-1,5)%O (at.%) and subjected to heat treatment. Based on the analysis of formation patterns of the crystallographic texture in foils as a result of their cold rolling, the main mechanisms of plastic deformation, which are activated in the listed alloys, are revealed. The variation of the annealing temperature in the range of 550–700${}^\circ$C allows changing the structure and the +crystallographic texture of the deformed foils due to the activation of various processes during annealing and, thus, the functional and mechanical properties of the material. Tests of the foils examined under tension and under cyclic loading (stretching up to a strain of 2.5%, followed by complete unloading of the sample) along and across their rolling direction confirm the presence of anisotropy of the manifestation of superelasticity effect in the materials. It is shown that this effect is orientational and structurally dependent.