Optimizing age hardening treatment for Monel K500 by phase field modelling

In this study, attempts are made to optimize the heat treatment cycle for Monel K500, a precipitation-hardenable nickel-copper alloy, to enhance hardness and wear resistance. Phase field modeling, thermodynamic simulations, and experimental validation were conducted to analyze precipitation kinetics and microstructural evolution. Thermo-Calc was used to generate phase diagrams, predict phase fractions, and calculate Gibbs free energy, guiding phase field modeling in MATLAB based on the Cahn-Hilliard and Allen-Cahn equations. Simulations predicted γ’ precipitate nucleation and growth at various aging conditions, leading to an optimized heat treatment: solutionizing at 800°C for 2 hours, followed by aging at 250°C, 450°C, 550°C, and 650°C for 8 hours. Experimental validation included hardness testing, X-Ray Diffraction (XRD), optical microscopy, and wear testing (ASTM G99). Results conclude that the optimized condition of 550°C at 8 hours shows improved hardness and wear resistance due to controlled γ’ precipitation. This integrated approach provides a reliable method for optimizing heat treatment in precipitation-hardenable alloys for high-performance applications.