On the Hierarchy of Structural-Phase States of 1561 Aluminum Alloy

Abstract

An experimental issue of studying the structural and deformation properties of an initially anisotropic 1561 alloy within a wide temperature-rate range is considered. In the course of realization of the experiments on “Gagarin’s” samples cut out in the rolling direction, the circular cross sections of the samples took an elliptical form. As a macro-characteristic of the material reflecting the occurring structural changes, the anisotropy factor is taken, which is represented by the ratio of deformations measured along the small and large axes of the cross section. Previously unknown regularities of the change in the anisotropy factor were established at the temperature increase under different values of the degree and strain rate. An essential dependence of the anisotropy factor on the thermomechanical conditions of deformation is noted. At high homological temperatures, the thermal range corresponding to the manifestation of superplastic properties is identified. Here, the anisotropy index tends to a minimum value. A correspondence between the results of mechanical experiments and the study of the structural state of the alloy was established. The obtained results indicate the dependence of the anisotropy factor on the initial structure of the alloy. The anisotropy factor can be taken as one of the macroparameters of the material that correspond to structural transformations and allow one to quantify the degree and completeness of structural changes relative to the initial state in a changing field of temperatures and strain rates.