Development of a simulation approach to microstructure evolution during solidification and homogenization using the phase field method

A numerical method for the simulation of microstructure formation during the solidification and solution heat treatment of single crystal superalloys is presented. The method is based on the phase-field method, coupled to thermodynamic calculation (CALPHAD) and kinetic databases. Simulations are performed in a representative transverse section of a directionally solidified dendritic array. Calculated as-cast structures form the bases for the subsequent solution heat treatment simulations. The method is applied to simulate microstructure fromation in a five component model Ni-base superalloy (Ni-5.8Al-9.10Cr-7.9TA-8.8W, wt.%). Experiments were carried out for validation and good agreement with the model predictions is observed.