Multiscale measurements on temperature-dependent deformation of a textured magnesium alloy with synchrotron x-ray imaging and diffraction

In situ synchrotron x-ray imaging and diffraction are used to investigate deformation of a rolled magnesium alloy under uniaxial compression at room and elevated temperatures along two different directions. The loading axis (LA) is either perpendicular or parallel to the normal direction, and these two cases are referred to as LA perpendicular to < c > and LA parallel to < c > loading, respectively. Multiscale measurements including stress-strain curves (macroscale), strain fields (mesoscale), and diffraction patterns (microscale) are obtained simultaneously. Due to initial texture, {10 (1) over bar2} extension twinning is predominant in the LA perpendicular to < c > loading, while dislocation motion prevails in the LA parallel to < c > loading. With increasing temperature, fewer {10 (1) over bar2} extension twins are activated in the LA perpendicular to < c > samples, giving rise to reduced strain homogenization, while pyramidal < c + a > slip becomes readily activated, leading to more homogeneous deformation for the LA parallel to < c > loading. The difference in the strain hardening rates is attributed to that in strain field homogenization for these two loading directions. (C) 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.