Temperature-dependent γ′ kinetic evolution and elemental partitioning in a novel CoNi-based superalloy: an integrated CALPHAD, phase-field, and experimental study

. By implementing a screening framework governed by seven distinct thermodynamic and kinetic criteria, we successfully eliminated deleterious TCP phases while maintaining a high γ' volume fraction of 70%. A transformative concept, temperature-activated microstructural adaptability, is introduced, where elevated temperatures from 1074 to 1124 K trigger a reversible redistribution of Ti and Al atoms between the γ and γ' phases. Phase-field simulations validated by experimental characterization reveal that this element redistribution dynamically optimizes the lattice mismatch from 0.803% to 0.725%, effectively balancing the internal elastic strain and interfacial energy. Consequently, the alloy exhibits an exceptional yield strength of 1275 MPa at a high temperature, surpassing conventional Co-Al-W-based superalloys and showing superior strength than the commercial Ni-based single crystals. This work provides a generalized paradigm for designing adaptive, high-performance structural materials through the synergy of multi-component thermodynamic and kinetic evolution.