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

该方案涉及模型和实验，以研究铸件中的微疏松。目的是了解微孔生长和合金液相对流流动对微观组织形成的影响。已经制定了三项截然不同的任务。第一种是用相场法模拟枝晶生长、微孔形成和熔体流动之间的相互作用。这些结果将被耦合到一个宏观模型中，用于预测微孔的成核、生长、团聚和迁移。最后，将在橡树岭国家实验室进行实验，为验证预测提供数据。如果研究成功，将有助于从根本上理解微孔的形成。商业铸造代码开发商可以使用要开发的计算机代码来提高与凝固处理的这一重要元素相关的建模能力。本奖项将集中于微孔洞形成的微观模型，并开发将该模型与宏观模型相结合的方法。还将进行验证实验的规划，以期在未来与ORNL进行广泛的合作。

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.