An ultra-high strength Mg-3Al-Zn alloy with low tension-compression yield asymmetry

•An ultra-high strength Mg-3Al-Zn alloy with low anisotropy was fabricated by mechanical milling, hot-press consolidation and extrusion.•The partially nanocrystallized structure was characterized by TEM.•The nanoscale and coherent MgO precipitates in the Mg matrix was characterized by TEM.•The macro-texture of the as-extruded alloy was analyzed by XRD. An ultra-high strength Mg-3Al-Zn alloy with low tension-compression yield asymmetry was successfully fabricated through adding 0.2 wt% MgO. The as-extruded alloy exhibits a tensile yield stress of 459 MPa, an ultimate tensile strength of 519 MPa, an elongation to failure of 3.2%, and a low tension-compression yield asymmetry of 1.01. The combined effect of partially nanocrystallized structure, nanoscale and coherent MgO precipitates, and ultra-fine recrystallized Mg grains results in the ultra-high strength and further results in the low tension-compression yield asymmetry with additional effect of weak basal texture.