Large-scale simulation of dendrite growth in directional solidification castings (Phys. Status Solidi B 10/2017)

Abstract

The modified shape function dendritic (MSFD) model was built to simulate the growth of a large number of dendrites in directional solidification (DS) in casting scale. The cover figure (cf. article no. 1600860 by Hang Zhang and Qingyan Xu) shows experimental dendritic morphologies in cross and longitudinal sections fitted by the numerical results with different pre-set Euler angles (φ1, ψ, φ2). The results agreed well, which proved that the transform matrix M was suitable for the dendritic morphology description. For the DS process, an MSFD model coupled with macro models was proposed to simulate the growth of thousands of micro dendrites and their distribution. Furthermore, the crystal selection of the spiral selector is clearly represented by the simulation method that employed the MSFD model, and the findings reveal the distribution of dendrites within the thinnest wall of a single-crystal turbine blade and the solidification sequence of the dendrites. Hence, the modified model coupled with macro-simulation models can be used to predict the morphology and distribution of DS dendrites with respect to large-scale castings produced by the DS process.