Excellent mechanical properties of an ultrafine-grained quasicrystalline strengthened magnesium alloy with multi-modal microstructure

In this study, we have developed an excellent mechanical properties of an ultrafine-grained quasicrystalline strengthened magnesium alloys by conventional extruding as-casted Mg-1.5Zn-0.25Gd (at%) ingot at 373 K with an extrusion ratio of about 9:1. After extrusion, multi-modal microstructure was formed, i.e. exhibited large deformed grains surrounded by fine dynamical recrystallization grains and the mean grain sizes smaller than 1 μm. The extruded sample shows excellent tensile properties at ambient temperature with ultimate tensile strength of 417 MPa, 0.2% proof stress of 395 MPa and elongation to failure of 8.3%. The notable improvement in strength mainly attributed to the grain refinement, dense distribution of the fine precipitates inside the fine dynamical recrystallization grains and the high intensity of typical basal texture.