Pseudo-elastic strain estimation of textured TiNi shape memory alloys

Abstract

In this paper, the texture and pseudo-elastic strain anisotropy of TiNi shape memory alloys have been studied. Orientation distribution functions (ODF) were first calculated using iterative series expansion method from incomplete pole figures measured by X-ray texture goniometers. Crystallographic textures and tensile pseudo-elastic strains at different angles were correlated by the method of statistically averaging the strains in the tensile axis contributed by every constituent grain according to the axis-symmetric strains of free and constrained single crystals. The calculated and experimental strains were well compatible and reached the respective maximums in the same angular range. The discrepancy between theory and experiment is explained by the redistribution of slip system orientations caused by texturing. In terms of the texture analysis and pseudo-elastic strain prediction, we can efficiently control the textures of shape memory alloys and optimally utilize the shape memory effects.