On the origins of the anisotropic mechanical behaviour of extruded AA2017 aluminium alloy

Abstract

This paper presents some experimental investigations about the origins of the anisotropic behaviour in cyclic loadings of AA2017 aluminium alloy. In the first step, fatigue damage evolutions were quantified for controlled proportional cyclic loadings in axial and shear directions. In this stage, the aim was to confirm the anisotropic mechanical behaviour, which has recently been revealed. To this end, several models of fatigue damage quantification were used. After a comparative study between the obtained results we confirmed the anisotropic nature of the used material. In the second step, microstructural investigations were performed in order to understand the origins of the anisotropic mechanical behaviour. We used scanning electron microscopy to analyse phases and precipitates in the transversal and the longitudinal sections. It was deduced that the structure and the morphology of these entities are responsible for the anisotropic behaviour of the used aluminium alloy. Moreover, the results obtained using Kikushi diagrams, poles figure and inverse poles figures have also confirmed these conclusions. Indeed, these results have shown great differences in crystallographic texture of the material.