The dynamic plasticity and dynamic failure of a magnesium alloy under multiaxial loading

This paper examines the anisotropic and rate-dependent mechanical behavior of a rolled AZ31B magnesium alloy under multiaxial loading over a wide range of strain rates ranging from 10(-4) to 10(5)s(-1). It is shown that stress state, strain rate as well as loading orientation collectively influence the plastic flow. The rate dependence of the plastic flow in the material varies with the loading orientation. The texture induced anisotropy, however, changes very little with the strain rate. The microstructures of the as received and deformed specimens suggest that detailed analysis of initial spread in textures is necessary, especially under multiaxial stress states. The failure mechanisms are also observed to evolve with loading rate. Our results provide useful insights into the deformation and failure mechanisms in magnesium and extend the understanding of the mechanical properties of magnesium to the ultra-high strain rate regime (10(5)s(-1)). (C) 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.