A Semiquantitative Model on Quick Estimation of the Structural Refinement by Ultrasonic Melt Treatment in Aluminum Alloys

Scaling industrial applications of the ultrasonic melt treatment (UMT) method for refining the solidification microstructure of metals has faced challenges, despite being proposed decades ago. A significant bottleneck is the need for a rapid pre-estimation of refinement. In this study, we present a semiquantitative model that facilitates this estimation. The model overcomes the time-consuming computations associated with dynamic cavitation regions by introducing a representative zone and extends its applicability by employing the empirical classic homogeneous theory for nucleation quantification. A case study involving aluminum alloys reveals an important finding: The refining efficiency of UMT peaks at approximately 120–140 MW/m² within an acoustic intensity range of 0–150 MW/m². Increasing the intensity beyond 150 MW/m² does not significantly enhance efficiency. This work addresses the engineering need for a quick pre-estimation of microstructure refinement via UMT and promotes diverse applications by further exploring the method.