On simulating diffusional phase transformation in diffusion triple

Abstract

Diffusion triple technique (stand-alone or composed diffusion multiples) is crucial for high-throughput construction of phase diagrams or extracting diffusion coefficients, taking advantage of the broad two-dimensional (2D) composition variations. However, currently there is a lack of methods available for simulating 2D diffusion accompanied by phase transformations inside diffusion triples. In the present work, we take a noticeable step forward by simulating diffusional phase transformation between the contacting interfaces, especially in the tri-junction of diffusion triple. The present method is an extension of the homogenization model (H. Larsson and L. Höglund, Calphad, 33 (2009) 495–501) to 2D simulations, allowing for disclosure of microstructure evolutions in diffusion triples. The practicability of the present method is demonstrated by comparing the simulation results with the experiment of a Fe-Cr-Ni diffusion triple (as a part of a multiple) from the literature.