Rotating Directional Solidification of Ternary Eutectic Microstructures in Bi-In-Sn: A Phase-Field Study

Abstract

For the first time, the experimental processing condition of a rotating directional solidification is simulated in this work, by means of a grand-potential-based phase-field model. To simulate the rotating directional solidification, a new simulation setup with a rotating temperature field is introduced. The newly developed configuration can be beneficent for a more precise study of the ongoing adjustment mechanisms during temperature gradient controlled solidification processes. Ad hoc, the solidification of the ternary eutectic system Bi-In-Sn with three distinct solid phases α,β,δ is studied in this paper. For this system, accurate in situ observations of both directional and rotating directional solidification experiments exist, which makes the system favorable for the investigation. The two-dimensional simulation studies are performed for both solidification processes, considering the reported 2D patterns in the steady state growth of the bulk samples. The desired αβαδ phase ordering repeat unit is obtained within both simulation types. By considering anisotropy of the interfacial energies, experimentally reported tilted lamellae with respect to normal vectors of the solidification front, as well as predominant role of αβ anisotropy in tilting phenomenon, are observed. The results are validated by using the Jackson–Hunt analysis and by comparing with the existing experimental data. The convincing agreements indicate the applicability of the introduced method.

Phase-Field Simulation of the Microstructure Evolution in the Eutectic Alloy NiAl-31Cr-3Mo

“…Due to the simplifications made in the description of the thermodynamic energies, their accuracy has to be checked. Following the validation from Noubary et al [15], the subplots in Figure 2 show the equilibrium concentrations calculated from the CALPHAD database (solid lines) and from the Equations ( 10)-( 12) (symbols), respectively. For all four concentrations an excellent accordance can be found not only in the predefined temperature range between T 1 and T 2 (gray area) but also up to eutectic temperature T eut , marked with a red dotted line, and also down to 15 K below T 1 .…”

“…Within this method, partial differential equations are numerically solved to simulate the phase transfer process during solidification driven by diffusion and phase transformations [3][4][5][6]. In the last decade, the directional solidification of several binary [7,8] and ternary systems [7][8][9][10][11][12][13][14][15] have been examined in two-and three-dimensional large-scale phase-field simulations.…”