Phase-field simulation of evolution of interfacial morphology and microstructure for Ti-45%A1 alloy

The phase-field model was used to simulate the evolution of interfacial morphologies and microstructures for Ti-45%A1 alloy during directional solidification at high speed close to absolute stability. The simulating results show that the fine cells are formed through the destabilization of the initial planar interface. As the growth velocity increases to the growth rate of absolute stability interface, the interface morphology transforms from fine cells to a high-speed planar interface. The investigation of solute distribution pattern indicates the appearance of microstructure of low microsegregation due to solute trapping at the interface. The simulating results are in good agreement with the theory results of rapid solidification.