Investigation of Interaction Between Dendritic Crystal Growth, Microporosity Formation, and Melt Convection on Micro and Macroscales

North Carolina State University, Raleigh NC

Investigators

Abstract

The proposal deals with models and experiments to study microporosity in casting. The goal is to understand how microstructure formation is influenced by microporosity growth and convective flow of an alloy liquid phase. Three distinct tasks have been laid out. The first is to use a phase field method to simulate the interaction among dendritic growth, microporosity formation and melt flow. These results will be coupled into a macroscopic model for predicting microporosity nucleation, growth, agglomeration, and migration. Finally, experiments will be conducted at Oak Ridge National Laboratory to provide data for validation of the predictions. If successful, the research will contribute to the fundamental understanding of microporosity formation. The computer codes to be developed could be used by commercial casting code developers to improve the modeling capability with respect to this important element of solidification processing. The present award will concentrate on the microscale modeling of microporosity formation and on developing the methodology for coupling this model with a macroscopic model. Planning for validation experiments will also be carried out, in anticipation of a future extensive collaboration with ORNL.