Martin Palm

Max-Planck-Institut für Eisenforschung, Düsseldorf, Germany

Abstract

Besides standard analysis by EDS or WDS, also more advanced techniques can be employed for the analysis of diffusion couples. By transmission electron microscopy (TEM) the couples cannot only be analysed in higher resolution, but features like phase transformations that could not be avoided by cooling/quenching become visible. Besides determining compositions by TEM-EDS, also the crystallographic structures of the phases can be identified. The latter is also possible by local X-ray diffraction or by electron-backscatter diffraction (EBSD). Compositional analysis with even higher spatial resolution can be performed by atom probe tomography (APT).

It has been shown in the lectures on Diffusion Theory how interdiffusion coefficients can be calculated. For their evaluation from diffusion couples, determination of the position of the Matano plane maybe necessary as a first step. Tracers or inert markers can also be employed to derive kinetic data from a diffusion couple.