Reaction diffusion and interdiffusion in some binary metallic systems

Abstract

This paper reviews studies from the Münster laboratory on multiphase and interdiffusion performed on several binary metallic systems. Optical microscopy and electron microprobe analysis were used to study interdiffusion and growth of the intermetallic layer(s) in infinite diffusion couples. Both methods have resolutions at the micron level. Thus, the results summarised in this paper concern the diffusion-controlled regime of the reaction diffusion process. We first remind the reader of some of the basics of multiphase diffusion and interdiffusion. Then we discuss results reported for the following systems: cobalt–niobium, nickel–niobium, nickel–aluminium and magnesium–aluminium. In the case of Co₂Nb we also compare interdiffusion and tracer diffusion of the components. Multiphase diffusion experiments also contain information about solid–solid equilibria of the phase diagram(s).

Keywords:

• multiphase diffusion
• interdiffusion
• tracer diffusion
• growth constant
• Laves phase
• solid–solid phase equilibria
• phase diagram
• binary metallic system

Acknowledgements

One of the authors (H.M.) is grateful for the contributions of former PhD students and co-workers: Drs. U. Schoo, W. Sprengel, M. Denkinger, and E.M. Tanguep-Njiokep. H.M.is also grateful to Profs. W. Sprengel and R. Würschum for the invitation to join the Institut für Materialphysik at Graz University of Technology, Austria, as visiting professor in May 2012.