The accuracy of a 2D and 3D dendritic tip scaling parameter in predicting the columnar to equiaxed transition (CET)

7th European Thermal-Sciences Conference

Seredyski, M.^1 ; Rebow, M.^2 ; Banaszek, J.^1

Faculty of Power and Aeronautical Engineering, Warsaw University of Technology, Nowowiejska 24, Warsaw

00-665, Poland^1

College of Engineering and Built Environment, Dublin Institute of Technology, Bolton Street, Dublin 1, Ireland^2

关键词: Aluminium-based alloy;    Columnar to equiaxed transition;    Dendritic growth models;    Kinetics modeling;    Metallic alloys;    Numerical calculation;    Scaling parameter;    Stability constants;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/745/3/032074/pdf
DOI  :  10.1088/1742-6596/745/3/032074

来源: IOP

【 摘 要 】

The dendrite tip kinetics model accuracy relies on the reliability of the stability constant used, which is usually experimentally determined for 3D situations and applied to 2D models. The paper reports authors' attempts to cure the situation by deriving 2D dendritic tip scaling parameter for aluminium-based alloy: Al-4wt%Cu. The obtained parameter is then incorporated into the KGT dendritic growth model in order to compare it with the original 3D KGT counterpart and to derive two-dimensional and three-dimensional versions of the modified Hunt's analytical model for the columnar-to-equiaxed transition (CET). The conclusions drawn from the above analysis are further confirmed through numerical calculations of the two cases of Al-4wt%Cu metallic alloy solidification using the front tracking technique. Results, including the porous zone-under-cooled liquid front position, the calculated solutal under-cooling and a new predictor of the relative tendency to form an equiaxed zone, are shown, compared and discussed two numerical cases. The necessity to calculate sufficiently precise values of the tip scaling parameter in 2D and 3D is stressed.