It is investigated that the effect of power ultrasound on solidification process,alloy structures and mechanical properties of Al-1%(mass fraction)Si alloy with horizontal continuous casting under ultrasonic field.Ultrasonic cavitation,the major mechanism of ultrasonic refining,is also discussed in detail.The results reveal that application of power ultrasound can increase the nucleation rate,refine alloy structures,and improve the mechanical properties.With increasing of ultrasonic power,the homogenous and...