A 3D discrete-element model for simulating liquid feeding during dendritic solidification of steel

Joint 5th International Conference on Advances in Solidification Processes;5th International Symposium on Cutting Edge of Computer Simulation of Solidification, Casting and Refining

土木建筑工程;计算机科学

Feng, Yi^1 ; Zalonik, Miha^2 ; Thomas, Brian^3 ; Phillion, André^1

Department of Materials Science and Engineering, McMaster University, Hamilton, Canada^1

Université de Lorraine, CNRS, IJL, Nancy

F-54000, France^2

Department of Mechanical Engineering, Colorado School of Mines, Golden, United States^3

关键词: Carman-Kozeny equation;    Dendritic solidification;    Discrete element modeling;    Engineering alloys;    Hot tearing susceptibility;    Representative volume element (RVE);    Solidification simulation;    Voronoi tessellations;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/529/1/012031/pdf
DOI  :  10.1088/1757-899X/529/1/012031

来源: IOP

【 摘 要 】

A 3D meso-scale discrete-element model has been developed to simulate fluid flow during dendritic solidification of steel. The model domain is a representative volume element consisting of a set of equiaxed dendritic grain envelopes along with extra-dendritic liquid channels, where the final grain shape is given by a Voronoi tessellation. Solidification of each grain is simulated via a volume average approach. The output of the solidification simulation at a given solid fraction is used as the input mesh for the fluid flow simulation. A single domain Darcy-Brinkman model is used to calculate the pressure field within the liquid channels, with Poiseuille flow assumed to occur in the extra-dendritic region, and Darcy flow assumed to occur within the dendrite envelope. Mass conservation over each element is then used to derive a flow equation that is solved via the finite element method. The results of this new model are first compared with a previously-developed granular model [1] where fluid flow only occurs between the grains, and then compared with different forms of the Carman-Kozeny equation. It is shown that the intra-dendritic liquid fluid flow plays a major role in the semi-solid pressure field, and thus needs to be included when investigating hot tearing susceptibility in engineering alloys undergoing dendritic solidification.