Microstructure, mechanical properties and corrosion behavior of quasicrystal-reinforced Mg-Zn-Y alloy subjected to dual-frequency ultrasonic field

The dual-frequency ultrasonic field (DUF) was employed to refine the quasicrystal-reinforced Mg-Zn-Y alloy. Microstructural evolution, corrosion behavior and mechanical properties of as-cast Mg-Zn-Y alloys with and without DUF treatment were investigated. Results reveal that the DUF treatment can refine the alpha-Mg grain and the I-phase dramatically. Consequently, the corrosion resistance and the mechanical properties were improved. The increase of segregation of solute Zn element at grain boundaries and the morphology change of I-phase should respond for the promoting of corrosion resistance. The improvement of tensile strength can be ascribed to the tremendous grain refinement and strengthening effect of tiny I-phase quasicrystals.