Ultrasonic modulation of phase separation and corrosion resistance for ternary Cu-Sn-Bi immiscible alloy

•Without ultrasonic field, a layered structure with clear boundary is obtained.•The macrosegregation is remarkably reduced within ultrasonic field.•The ultrasonic cavitation contributes to the refinement of secondary particles.•The acoustic streaming enhances the uniform distribution of secondary particles.•Ultrasound improves the corrosion resistance and mechanical properties of alloy. The effect of power ultrasound on the liquid phase separation of ternary Cu-32%Sn-20%Bi immiscible alloy is experimentally investigated, which shows that as compared with the layered structure formed under static condition, the macrosegregation resulted from liquid phase separation is remarkably reduced with the increase of ultrasonic amplitude. A homogenous microstructure characterized by refined (Bi) particles dispersing uniformly on the (Cu3Sn) matrix is obtained when the ultrasonic amplitude reaches the highest value of 24 μm. This is mainly ascribed to the ultrasonically induced cavitation and acoustic streaming, which promotes the nucleation, the fragmentation, and the dispersion of (Bi) droplets. The finally solidified immiscible alloy exhibits obvious improvements in electrochemical corrosion resistance, microhardness and wear-resisting if compared with those in static solidification. These results prove that applying power ultrasound is an effective way to modulate the liquid phase separation and enhance the applied performance for immiscible alloys.