Simulation of the solidification of CMSX-4

The solidification and cooling of the nickel–base alloy CMSX-4 during casting was simulated using a one-dimensional model for diffusion-controlled phase transformations. A temperature interval from the liquidus temperature to 800 K is covered, including solid state transformations. This paper discusses several results: fraction solid compared to results from Scheil and equilibrium calculations, microsegregation profiles for Al, Co, Cr, Re, Ta, Ti and W compared to experimental values, and the formation of finely dispersed γ ′ -phase in the solid state. The relatively simple one-dimensional diffusion simulation is shown to be a valuable tool to investigate phase formation and microsegregation during solidification and cooling. In the case of CMSX-4 it represents a significant improvement over the commonly used Scheil calculations for the prediction of the fraction solid.