Effect of thermal-mechanical processing on microstructure and mechanical properties of duplex-phase Mg-8Li-3Al-0.4Y alloy
(1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. School of Materials Science and Engineering, McGill University, Montréal, Québec, H3A 0C5, Canada;
3. Division of Materials Engineering, School of Mechanical and Mining Engineering, The University of Queensland, Brisbane, QLD 4072, Australia)
Abstract: The effect of thermal-mechanical processing on the microstructure and mechanical properties of the duplex phase Mg-8Li-3Al-0.4Y alloy was investigated. The as-cast alloy was composed of α-Mg, β-Li, AlLi, Al2Y and MgAlLi2 phases. Annealing of the cold rolled alloy at 350 °C for 60 min was considered to be optimum. This caused full static recrystallization and spheroidization. A significant β-Li loss occurred when the annealing time was increased to 90 min. The optimized annealing treatment produced the following values of the yield strength, ultimate strength and elongation: 148 MPa, 184 MPa and 35%, respectively. The texture evolution of the α-phase and the β-phase changed remarkably during thermal-mechanical processing.
Key words: Mg-Li alloy; recrystallization; spheroidization; β-Li loss; texture