Spinodal Decomposition Mechanism of γ′ Precipitation in a Single Crystal Ni-Based Superalloy
Résumé
The precipitation of γ′ phase in a commercial single crystal Ni-based superalloy with different cooling rates has been investigated by atom probe tomography. Numerous irregular interconnected γ′ precipitates in the size range of ~30 to 50 nm were obtained even utilizing the fastest possible cooling rate. Diffuse γ/γ′ interface and far from equilibrium composition of γ′ phase were observed in the fast-cooled sample, suggesting that γ′ precipitation occurs via a spinodal decomposition at the very early stage.