Interface segregation in metals
In metals and alloys, solute atoms sometimes segregate to interfaces (surfaces, grain boundaries, interphase boundaries). As this alters the interface cohesion, it can result in a dramatic degradation of the material mechanical properties.
- Understand and model interface segregation in equilibrium and non-equilibrium conditions.
- Determine (from experiments) the thermodynamics and kinetics parameters of segregation in various systems and conditions, including model systems as well as industrial materials and processes.
- Develop new experimental approaches for the quantification of interface segregation
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| Auger spectrum acquired on a stainless steel fracture surface. The grain boundary segregation of phosphorus is demonstrated. |
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| NanoSIMS observation of sulphur grain boundary segregation in nickel. |
Recent references:
Ultra-fast sulphur grain boundary segregation during hot deformation of nickel. M. Allart, F. Christien, R. Le Gall, Acta Materialia 61 (2013) 7938-7946.
A multi-technique investigation of sulphur grain boundary segregation in nickel. M. Allart, F. Christien, R. Le Gall, P. Nowakowski, C.R.M. Grovenor, Scripta Materialia 68 (2013) 793-796.
Quantification of equilibrium grain boundary segregation by NanoSIMS analysis of bulk samples. F. Christien, C. Downing, K.L. Moore, C.R.M. Grovenor, Surface and Interface Analysis 44 (2012) 377-387.
Ultra-fast grain boundary diffusion and its contribution to surface segregation on a martensitic steel. Experiments and modelling. F. Christien, R. Le Gall, Surface Science 605 (2011) 1711-1718
Measuring grain boundary segregation using Wavelength Dispersive X-ray Spectroscopy: further developments. P. Nowakowski, F. Christien, M. Allart, Y. Borjon-Piron, R. Le Gall, Surface Science 605 (2011) 848-858.
Quantifying the effect of fracture surface topography on the scattering of grain boundary segregation measurement by Auger electron spectroscopy. F. Christien, Y. Borjon-Piron, R. Le Gall, S. Saillet, Materials Characterization 61 (2010) 73-84.
Books:
Endommagement interfacial des métaux - Ségrégation interfaciale et conséquences. G. Saindrenan, R. Le Gall, F. Christien, Edition Ellipses, Collection Technosup. 256 pages. 2002.
The use of Electron Probe MicroAnalysis to determine the thickness of thin films in materials science. F. Christien, E. Ferchaud, P. Nowakowski, M. Allart, In "X-Ray Spectroscopy" (2012) Shatendra K. Sharma (Ed.), ISBN: 978-953-307-967-7, InTech.
Current or recent collaborations:
- Department of Materials, University of Oxford, UK (Prof. C. Grovenor)
- Aperam, Imphy, France.