MSIT Winter School

MSIT Winter Schools comprise lectures given by the MSIT members and invited experts on Phase diagrams, Classical and Computational Thermodynamics, and Crystallography and related applicational topics.

Preparation, Heat Treatment and Analysis of Diffusion Couples

Martin Palm

Max-Planck-Institut für Eisenforschung, Düsseldorf, Germany



In this lecture, basic considerations about the assembly of diffusion couples, how these are handled in practice and standard analysis of the diffusion path are discussed.

Choice of suitable starting compositions, whether these will be in the form of e.g. a solid-solid or a solid-liquid diffusion couple and if a marker or tracer is needed have to be considered in the beginning. Various types of assembly are possible, but always a good contact between the diffusion partners has to be attained and welding of the partners may have to be considered. While the temperatures for heat treatments are usually evident from the question to be solved, estimating the duration of the heat treatment usually is not straightforward.

Subsequent analysis of a diffusion couple typically starts with preparation of a section parallel to the diffusion path. Standard analysis by an energy or wavelength dispersive spectrometer (EDS, WDS) yields quantitative diffusion profiles. Finally, we will see how these diffusion profiles are evaluated, e.g. for the determination of phase boundaries.