The texture and anisotropy of magnesium–zinc–rare earth alloy sheets

In this paper, the rolling textures of six magnesium alloys containing different levels of zinc and rare earth (RE, e.g. mischmetal or Y) additions are examined. The overall texture strength and the basal pole intensity aligned with the sheet normal direction is lower for RE-containing alloys than for conventional alloys. The distinct textures generated in this study allow the influence of texture on the mechanical response to be investigated. The anisotropy of the yield and flow strengths is reversed and the planar anisotropy is reduced (r ∼ 1) in comparison to conventional alloys. Both aspects of the anisotropy are related to the fact that the dominant texture components in the Mg–Zn–RE alloys place more grains in favourable orientations for basal slip and tensile twinning, particularly during transverse direction tension. Mg sheets with lower r-values should have improved forming behaviour, at least under straining conditions which call for thinning of the sheet.