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J. Svoboda, E. Gamsjaeger, F.D. Fischer, Y. Liu, E. Kozeschnik:
"Diffusion processes in a migrating interface: The thick-interface model";
Acta Materialia, 59 (2011), 12; 4775 - 4786.

During a solid/solid diffusive phase transformation from a parent b-phase to a product a-phase, dissipative processes due to diffusion
in the bulk phases as well as rearrangement of the crystal lattice and diffusion in the interfacial region occur. A model has been developed that accounts for all the above-mentioned dissipative processes. By means of this thick-interface model it is possible to assign a finite thickness and a finite mobility to the interface. The evolution of the mole fraction profiles of the components in the bulk phases and in the interface can be simulated from a given initial state until a steady state or equilibrium is attained. Based on this theoretical framework the kinetics of the c/a phase transformation in the Fe-rich Fe-Cr-Ni system is simulated. Starting from a certain initial composition the transformation kinetics exhibits the features of a massive or a bulk diffusion controlled transformation depending on temperature.

Modeling, Phase transformation, Diffusion, Interface migration, Thermodynamic extremal principle

http://dx.doi.org/10.1016/j.actamat.2011.04.020