Stray grain formation in casting platform of third generation Ni-base single crystal superalloy

For the model blade of a kind of 3rd-generation Ni-base single crystal superalloy, the temperature field distribution and grain microstructure evolutionary process with different withdrawal rate and platform dimension was observed. By ProCAST & CAFE numerical simulation and HRS directional solidification, the effect of withdrawal rate and platform dimension on stray grain formation was studied. The results show that the temperature field distribution near the solidification interface will be notably changed with the increased withdrawal rate and platform dimension. The stray grain will nucleate and grow at the platform edge due to the local undercooling. With the increased withdrawal rate and platform dimension, both the quantity and the size of the stray grain will increase.