An operator splitting scheme for coupling macroscopic transport and grain growth in a two-phase multiscale solidification model: Part II – Application of the model

Abstract

In this paper, the application of the two-phase solidification model with a splitting scheme for coupling macroscopic transport and grain growth, described in part I of this work, is presented with simulations of solidification of a binary alloy in a rectangular cavity. The splitting method is first verified by comparing the predictions with a classical directly coupled method. The verification is performed for a critical limiting case, as identified in part I, with infinitely fast microscopic diffusion (lever rule) and a fixed solid in the mushy zone. A further test is performed to show the capability of our model, where macroscopic transport and diffusion-controlled grain growth kinetics are coupled by the splitting scheme, in predicting recalescence. Thereafter, the complete model, as presented in part I, is applied to simulate solidification in its full complexity, considering the grain motion and grain growth kinetics. With the help of the model predictions the influence of the motion of globular solid grains on the transport phenomena during solidification and formation of macrosegregation is discussed.