Role of the structure and texture in the realization of the recovery strain resource of the nanostructured Ti-50.26 at %Ni alloy

In this work, we have studied the nanostructure, the crystallographic texture, and the crystal lattice of the martensite of the Ti-50.26 at % Ni alloy subjected to a thermomechanical treatment, which includes cold rolling, warm (at 150A degrees C) rolling, intermediate and post-deformation annealings (at 400A degrees C) in different combinations. To calculate the resource of the recovery strain in the approximation of a polycrystal, we suggested and employed a method based on the sufficiently complete allowance for the orientation distribution function of the initial B2 austenite and on the assumption on the realization of the most favorable orientational variant of martensite in each grain. The calculated values of the resource of the recovery strain have been compared with the experimental data and have been analyzed along with the results of the determination of the recovery stresses and parameters of the loading-unloading diagram. Estimations have been made of the role of the structural and textural factors in the realization of the recovery strain of the nanostructured Ti-50.26 at % Ni alloy. To achieve the maximally high recovery strain, one should focus on obtaining a nanocrystalline structure in combination with a sharp texture, which ensures the maximum transformation deformation in the direction of tension.