Nucleation Kinetics and Grain Refinement

Abstract

Abstract This article discusses selected highlights of thermodynamic relationships during solidification and nucleation kinetics behavior in connection with the basis of nucleation treatments, such as grain refinement and inoculation, to provide a summary of nucleation phenomena during casting. Nucleation during solidification is a thermally activated process involving a fluctuational growth in the sizes of clusters of solids. The article describes nucleation phenomenon such as homogeneous nucleation and heterogeneous nucleation. It discusses various grain refinement models, such as carbide-boride model, free growth model, and constitutional undercooling model. The article concludes with a section on thermal analysis techniques for assessing grain-refining characteristics during master alloy processing.