Microstructure and mechanical properties of twin roll cast AM31 magnesium alloy sheet processed by differential speed rolling

Twin roll cast AM31 alloys were rolled at a warm temperature of 350 °C and subsequently rolled at 300 °C using equal speed rolling and differential speed rolling with speed ratios of top roll to bottom roll, 1.2 and 1.5, respectively. Microstructures, textures and mechanical properties of the as-rolled AM31 sheets were examined. Ductility was improved by differential speed rolling due to inclined and weakened basal texture. Fine grain size and higher solution elements contents in the twin roll casted AM31 resulted in high ductility and strength in the rolled AM31 sheets. Texture characteristics inherited from the twin roll cast AM31 sheets had great influence on the evolution of microstructure and texture during the subsequent rolling and annealing process. Strength and ductility were improved by twin roll casting combined with differential speed rolling due to grain refining, inclination of basal poles and weakened texture.