Microstructures and mechanical properties of cold rolled Mg-8Li and Mg-8Li-2Al-2RE alloys

The microstructures and mechanical properties of Mg-8Li and Mg-8Li-2Al-2RE alloy sheets were evaluated after cold rolling. Both alloys contain α-phase and β-phase which consists of a solid solution of Mg in BCC Li. The proportion of β-phase in both alloys is approximately 60%. The α-phase and β-phase are elongated approximately parallel to the rolling direction and there is no sign of recrystallization even after being annealed at 200 °C for 1 h. The yield strength of Mg-8Li-2Al-2RE sheets is about 165 MPa with elongation of 35% along rolling direction, while the yield strength is about 187 MPa with elongation of 21% along the direction titled 45° to rolling direction. The α-phase in both alloys exhibits basal texture, and the intensity of basal texture in Mg-8Li is larger than that in Mg-8Li-2Al-2RE. However, the β-phase shows (100) texture, and the intensity of (100) texture in Mg-8Li is twice of that in Mg-8Li-2Al-2RE. It could be attributed to the existence of RE-containing particles in Mg-8Li-2Al-2RE.