DEVELOPMENT OF A SIMULATION APPROACH TO MICROSTRUCTURE EVO LUTION DURING SOLIDIFICATION AND HOMOGENIZATION USING THE PHASE F IELD METHOD

A numerical method for the simulation of microstructure formation during the solidification and solution heat treatmen t of single crystal superalloys is presented. The method is based on the phase-field method, coupled to thermodynamic calcula tion (CALPHAD) and kinetic databases. Simulations are performed in a representative transverse section of a directio nally 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-5.8Al9.0Cr-7.9Ta-8.8W, wt.%). Experiments were carried out for validation and good agreement with the model predictions is observed.