A. Engström, Q. Chen, L. Höglund, Thermo-Calc Software AB, Stockholm, Sweden; P. Mason, Thermo-Calc Software Inc, McMurray, PA
This paper discusses modelling and simulation of interdiffusion in Ni-base superalloy / NiAl-cotaing diffusion couples, by means of a thermodynamic and kinetic modelling approach as taken in a commercial finite-difference code, DICTRA[1]. This code solves the multi-component diffusion equations, combining assessed thermodynamic and kinetic data in order to determine the full composition dependent interdiffusion matrix. In this work, the so-called homogenization approach to diffusion in multi-phase systems[2] have been used in order to simulate interdiffusion in complex Ni-base superalloy / NiAl-coating diffusion couples. The simulation results obtained are validated against experimental data, and the agreement is very satisfactory given the complexity of the problem.
References:
1. J.O. Andersson, T. Helander, L. Höglund, P.F. Shi, and B. Sundman, Calphad, 26 (2002), pp. 273-312.
2. H. Larsson and A. Engström, Acta Materialia, 54 (2006), pp. 2431-2439.
Summary: This paper discusses modelling and simulation of interdiffusion in Ni-base superalloy / NiAl-cotaing diffusion couples, by means of a thermodynamic and kinetic modelling approach as taken in a commercial finite-difference code, DICTRA[1]. This code solves the multi-component diffusion equations, combining assessed thermodynamic and kinetic data in order to determine the full composition dependent interdiffusion matrix. In this work, the so-called homogenization approach to diffusion in multi-phase systems[2] have been used in order to simulate interdiffusion in complex Ni-base superalloy / NiAl-coating diffusion couples. The simulation results obtained are validated against experimental data, and the agreement is very satisfactory given the complexity of the problem.
