Effect of Ultrasonic Radiation on the Grain Refinement of High Purity Aluminum

Abstract

Effect of high-intensity ultrasonic irradiation on solidified structure of high purity aluminum was studied. The results reveal that the solidified structure was obviously divided into two regions: an effectively refined region I and a poorly refined region II. Cavitation induced nucleation was considered acting as a leading role in causing the final refinement. Re-distribution of cavitation induced nuclei by acoustic flow resulted in the cone-shape of the region I filled with remarkable columnar crystals.