DEGASSING EFFECT AND GRAIN REFINEMENT OF Al-Si ALLOY WITH POWER ULTRASOUND
超声场作用下Al-Si合金的除气效果及晶粒细化

The degassing effect and the grain refinement of Al-Si alloy with power ultrasound were studied. The value of porosity volume of Al-Si alloy decreases obviously when the treated time is 60s. The grains are fine and globular when the solidification of Al-Si alloy was treated by power ultrasound and the grains are fine but not globular at isothermal temperature in the mushy zone with ultrasonic vibrations. The results imply that the expansion and collapse of cavities which results in the formation of nuclei plays the dominant important role in the formation of fine and globular grains.