Morphology and kinetics evolution of γ′ and γ phases in Ni-xAl-(20‒x)Cr at% alloys

The morphology and kinetics evolution of γ′ and γ phases in Ni-xAl-(20‒x)Cr at% (x = 7.5–13.7) alloys aged at 700 °C were studied by utilizing the phase-field simulation. The separated γ′ phases from γ matrix in low Al content (x 13) alloys, and long-time aging produced near cubic γ′ phase. The coarsening rate of γ′ phase declined firstly when the Al content x = 7.5–9.0, then increased sharply as x ranges from 9 to 12, while the coarsening rate of γ phase declined directly. Additionally, the average edge-to-edge distance of neighboring γ′ phases showed a three-stage variation when Al content x