Another perspective on elastic and plastic anisotropy of textured metals

Abstract

In textured metals, the elastic directionality reflects the crystallographic organization, while the plastic flow follows the preferential pathways of deformation beyond the elastic limit. In here, the elastic and plastic anisotropies are characterized by two observers. One of them is immersed into the material and, while there, is unaware of the texture-induced reorganizations, still, is in a position to detect elastic distortions. Another observer is located outside the material, monitors the elastic strain too and realizes that texture makes the elastic responses directional. The externally measured elastic strain will be called the texture strain. The key idea is to determine the transformation rules that correlate the elastic strains seen by the two observers. In what follows, the rules are derived by projecting the texture-distorted basis onto the basis of the external observations. It turns out that the rules reproduce directionality of elastic properties and include constraints that result from the limits imposed by the yield stress. The elastic anisotropy is linked to the strain that is free of the plasticity-induced constraints. By contrast, the constraints enable complete characterization of the plastic flow directionality. The concept is derived in the framework of tensor representations discussed in the electronic supplementary material.