Mechanical properties and anisotropy of ME20 magnesium sheet produced by unidirectional and cross rolling

The microstructures and textures of 90% unidirectionally (UR) and cross rolled (CR) RE-containing magnesium alloy ME20 were investigated for different reductions per rolling pass (r.p.p). During cross rolling the strain path was changed between the rolling passes which led to a weaker texture development and a finer recrystallized grain size compared to conventional unidirectional rolling. The presence of Ce-containing second phase particles with micrometric sizes is suggested to facilitate recrystallization by particle stimulated nucleation (PSN). The tensile mechanical properties in terms of strength and ductility, and also the sheet anisotropy of the UR and CR rolled materials were investigated at room temperature. CR specimens showed enhanced ductility of 26% elongation-to-fracture and an average r-value close to 1, which was attributed to the soft sheet texture prior to tension.