High-throughput measurement and evaluation of diffusion behaviors in Fcc Ni–Al–Si alloys

To address the lack of kinetic investigations for the Ni–Al–Si system, which is essential for design of next-generation Ni-based superalloys, the diffusion behavior of 12 designed diffusion couples was systematically investigated across three temperatures (1273, 1373, and 1473 K). The interdiffusivities at twelve intersection compositions were determined by the classical M−K (Matano−Kirkaldy) method, yielding values of D ˜ A l A l N i ranging from 2.27 to 93.81 × 10 −15 m 2 /s and D ˜ S i S i N i ranging from 2.48 to 53.07 × 10 −15 m 2 /s across the temperature range of 1273-1473 K. The high-throughput evaluation of interdiffusivities and atomic mobilities in Ni–Al–Si system was conducted through CALTPP (CALculation of ThermoPhysical Properties) software. The atomic mobility parameters of the ternary system were optimized through the M−K method and NIM (numerical inverse method) module implemented in CALTPP. The optimized mobility parameters by NIM were subsequently applied to simulate the diffusion paths in the ternary phase diagram, fluxes, and composition profiles, clarifying the diffusion interactions that occur within the studied system. The excellent agreement between simulation and experiment demonstrates the predictive capability of the mobility parameters established in this study. Using the validated parameters, 3-D (3-dimensional) maps of interdiffusivities D ˜ A l A l N i , D ˜ S i S i N i , D ˜ A l S i N i , and D ˜ S i A l N i , Arrhenius pre-factor D 0 , and activation energy Q as functions of Si and Al compositions were also predicted. Representing the first comprehensive and validated kinetic parameters for the Ni–Al–Si system, the obtained data fill a critical gap in commercial databases and enable accurate simulations of microstructural evolution, phase transformations, and long-term stability in Ni-based superalloys.