A grand-potential based phase-field approach for simulating growth of intermetallic phases in multicomponent alloy systems

Intermetallic phase-based alloys, in particular transition-metal aluminides, are potential structural and coating materials for high-temperature applications. Such applications usually involve interdiffusion between two dissimilar materials. To simulate microstructures quantitatively, it becomes essential to solve alloy phase-field models conjunction with multicomponent CALPHAD databases. This coupling, however, still remains a challenge when considering binary or intermetallic phases. Here, novel method that incorporates successfully diffusion dependent-properties of bulk phases into grand-potential based multi-phase-field model is proposed. It uses phase-specific properties directly precomputed from CALPHAD-type databases as discrete functions solute potentials. Six different cases, ranging five-phase (Ni-Al) two-phase quaternary (Al-Cr-Ni-Fe) alloy, simulated illustrate the application correctness method. The cases include both substitutional Where comparison possible, simulations show good agreement DICTRA experimental results, thus validating our proposed In contrast approach, we find fails three involving ordered intermetallics. We further interface width this can be varied without accuracy loss, enabling computationally affordable at experimentally comparable length time scales.