Experimental and Numerical Bendability Analysis of a 3rd Generation Magnesium Alloy

Abstract

Motivated by the demand for lightweight materials, magnesium alloys in use for structural components in the automotive and aircraft industry are getting attention. In the current contribution, the bendability of the innovative magnesium alloy “E-form” AZ31 at room temperature is investigated by means of 3-point bending tests and respective numerical simulations. The bending tests were conducted for different orientations of the sample with respect to the sheets axes of orthotropy. The force-displacement records confirmed the plastic anisotropy of the material evidenced in tensile testing. The limits of bendability were given by cracking of the samples, which was found to be strongly direction-dependent. A correlation between bendability and Lankford coefficient was explored. The elastic-plastic deformation was modelled using finite elements and a two-yield-surface model, which is able to describe the evolving strength differential effect and the anisotropy. Approaches based on 1D, 2D and 3D discretisations were compared. Zones with tensile and compressive stresses were identified by microstructural changes and mapped with its numerically obtained counterparts.