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

Abstract 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 ⊥ 〈 c 〉 and LA ∥ 〈 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 ¯ 2 } extension twinning is predominant in the LA ⊥ 〈 c 〉 loading, while dislocation motion prevails in the LA ∥ 〈 c 〉 loading. With increasing temperature, fewer { 10 1 ¯ 2 } extension twins are activated in the LA ⊥ 〈 c 〉 samples, giving rise to reduced strain homogenization, while pyramidal 〈 c + a 〉 slip becomes readily activated, leading to more homogeneous deformation for the LA ∥ 〈 c 〉 loading. The difference in the strain hardening rates is attributed to that in strain field homogenization for these two loading directions.