Effect of Ultrasonic Power on Grain Refinement in Semi-continuous Casting of 7050 Aluminum Alloy

Aluminum alloy 7050 melt was treated by ultrasonic in the process of semi-continuous casting.The effects of different ultrasonic powers on the solidification structure of casted ingot were analyzed.And the mechanism of grain refinement by ultrasonic was discussed.The results show that the microstructure of 7050 aluminum alloy was obviously refined by the ultrasonic in the process of semi-continuous casting.The phenomenon was due to the ultrasonic cavitation and acoustic stream effects.The microstructure refinement was improved with the increase of ultrasonic power.