Temperature Field Evolution of Seeding during Directional Solidification of Single-Crystal Ni-Based Superalloy Castings

By combined numerical simulations and unidirectional solidification experiments, the temperature field evolution of seeding for nickel-based single-crystal superalloys was studied. At steady state, position mushy zone in seed moves down as melt is poured into mold. The holding time required segment to reach state less seeds with casting than those without casting. completely eliminate randomly oriented broken dendrites melt-back much longer that achieve a state. A short incubation stage before process; then, migration rate isotherm gradually increases until it vicinity withdrawal rate. Finally, effect on formation stray grains segments discussed.