Phase-field simulation of directional solidification in Ti-43Al alloy

The phase field modeling of L → β directional solidification in Ti-43Al binary alloy was established by coupling the thermodynamic databases to WBM model. Based on the model, the microstructure evolution in solidification process was successfully simulated. The influences of phase field parameters and solidification parameters on the interfacial morphology were analyzed. The simulated results show that, with the decrease of the anisotropy coefficient, the tip growth rate is decreased and branch growth is easier, which is in favor of formation of cellular structures. The grain growth is transformed from shallow cell to deep cell as a result of easy enrichment of solute at groove of cell grain with the interface thickness decrease. In addition, with the increase of the temperature gradient, the interfacial micro-structure evolution is transformed from deep cell to shallow cell, then to planar interface.