Effects of yttrium and zinc on the texture, microstructure and tensile properties of hot-rolled magnesium plates

Pure magnesium, Mg-Y (1, 3, 5) and Mg-1Zn alloy (nominal composition, in wt%) were selected to examine the influence of alloying on the microstructure, texture and mechanical properties of Mg plates after hot-rolling and subsequent annealing. It was found that the maximum intensity of the rolled texture was markedly decreased with increasing Y additions but slightly increased by the Zn addition, in comparison with that of pure Mg. The texture weakening efficiency of Y addition declined with increasing Y concentration. The weakening of texture in Mg-Y alloys was attributed to the solute-driven effect, manifest as solute segregation at grain boundaries, which was evidenced by the TEM examination. Tensile testing revealed that the Mg-1Y alloy exhibited the highest elongation-to-failure of 30% at room temperature, and EBSD analysis suggested that the observed high room-temperature ductility was attributed to the weakened texture which favored the operation of the basal slip and tensile twinning.