N. Warnken, R. C. Reed, University of Birmingham, Birmingham, United Kingdom

Summary: Turbine blades used in the high pressure sections of aero turbines are commonly made from Ni-base superalloys. In order to reveal their full potential, these parts are directionally solidified and subsequently heat treated. The solution heat treatment aims at removing the micro-segregation and non equilibrium phases, which inherited from the directional solidification process. The microstructure evolution during directional solidification and subsequent solution heat treatment of technical relevant superalloys is simulated using the phase field approach. By coupling to thermodynamic calculations the full complexity of the alloys is taken into account. From the simulation results the evolution of micro-segregation and phase fractions during the course of the processing is deducted. The predicted microstructure evolution is compared to experimental observations and the potential for solution heat optimisations is demonstrated.