Novel Mg-Al-Sn-Zn-Y Alloys With Enhanced Strength-Ductility Combination Prepared By Hard-Plate Rolling

Herein, novel high-performance Mg-Al-Sn-Zn-Y (ATZ821-xY) alloys are developed via hard-plate rolling (HPR). With the addition of Y, the heterogeneous grain structure of the HPRed ATZ821 alloy evolves to be more uniform, accompanied with significant weakening in basal texture. This is due to the faster dynamic recrystallization (DRX) induced by the particle-stimulated nucleation (PSN) effect from the Al2Y particles, pinning effect from well-dispersed submicrometer-sized precipitates including Mg17Al12 and Mg2Sn, and the slips activated by Y atoms in alpha-Mg. Correspondingly, the HPRed ATZ821-1.0Y alloy shows a good combination of strength and ductility, that is, a yield strength (YS) of approximate to 248 MPa, an ultimate tensile strength (UTS) of approximate to 385 MPa, and a uniform elongation (UE) of approximate to 20%. The high YS is mainly due to grain boundary strengthening, which accounts for approximate to 70% of the total YS. The high UE is mainly attributed to the strong work hardening associated with weakened basal texture, well-dispersed Mg17Al12 and Mg2Sn precipitates, as well as enhanced slips induced by Y atoms in the solid solution.