THE MICROSTRUCTURE AND TEXTURE DEVELOPMENT DURING TWIN ROLL CASTING AND ROLLING OF MAGNESIUM ALLOY AZ31

摘要

Twin-roll casting of magnesium alloys is seen as a promising processing route to enable a further development of sheet properties. In this regard the influence of melt temperature and rolling speed on the microstructure and texture development of magnesium strips is investigated for alloy AZ31. Microstructure and through-thickness texture measurements are used to reveal effects of grain growth during solidification and deformation of the strip. For this purpose synchrotron radiation at the PETRA III storage ring of DESY in Germany has been used. Twin-roll casting with varied processing parameters leads to microstructures ranging from directionally solidified grains to deformed microstructures with a profound fraction of recrystallized grains. Specifically, sheets rolled from different strips exhibit an alignment of their Mg basal planes in the sheet plane with certain significance depending on grain size and grain orientation effects.