Effect of thermal stability of γ′ phase on the recrystallization behaviors of Ni-based single crystal superalloys

The recrystallization may deteriorate the mechanical properties of single crystal superalloys greatly, which concerns the engineers and scientists in the aviation industry. Recrystallization behaviors after grit-blasting and annealing at different temperatures of a gamma'-richen experimental single crystal alloy IC32 (the as-cast and heat-treated) were investigated. Samples of the as-cast ones are less prone to recrystallization than the heat-treated ones. In the as-cast state, the interdendritic regions show a stronger resistance to recrystallization than the dendritic regions. According to the results, we can conclude that the size characteristics and thermal stabilities of the gamma'-phases play important roles in deciding the recrystallization resistances of the Ni-based single crystal superalloys.