Philippe Marcus, Luntao Wang, Vincent Deloris, Dimitri Mercier
Chimie ParisTech-CNRS, PSL University, Institut de Recherche de Chimie Paris, Research Group Physical Chemistry of Surfaces, 11 rue Pierre et Marie Curie, 75005 Paris France
Abstract: The alloys used in various industrial sectors must be protected against corrosion. The best corrosion resistant alloys are those protected by an oxide film formed at the surface, often only a few nanometers thick. Chromium-containing alloys are very effective in this respect.
High Entropy Alloys constitute a new class of materials, originally comprising five or more elements in equiatomic concentrations, based on the idea that a high configuration entropy allows us to stabilize a single phase that would otherwise not be stable. They are promising because they have very good mechanical properties. However there is a very limited knowledge on their corrosion behavior, although corrosion resistance is key to material durability, particularly in chemically agressive environments.
In this work, the corrosion behavior of the CoCrFeMnNi High Entropy Alloy was studied by combining electrochemical methods with two surface characterization techniques, X-ray Photoelectron Spectroscopy (XPS) and Time-of-Flight Secondary Ions Mass Spectrometry (ToF-SIMS). A new XPS methodology based on the analysis of the 3p core level spectra was developed to determine the composition and thickness of the surface oxide films. Both the native oxide and passive films formed on the HEA have been investigated.
The following points will be addressed:
- Chemical states of the elements
- Layered structure of the surface oxide films
- Distribution of alloying elements in the oxide film and in the modified layer underneath
- Oxide film thickness
- Effect of grain size
In the light of these data, the protection against corrosion of HEA alloys will be discussed, as well as the needs for future work.
Pr. Marcus is Head of the Research Group of Physical Chemistry of Surfaces of Institut de Recherche de Chimie Paris, Ecole Nationale Supérieure de Chimie de Paris, Chimie ParisTech, France. Dr Marcus received his Ph. D. (1979) in Physical Sciences from University Pierre and Marie Curie, Paris, France.
His field of research is surface chemistry, surface electrochemistry, and corrosion science, with emphasis on the understanding of the structure and properties of metal and alloy surfaces and thin oxide layers.
His research interests include the growth mechanisms and structure of oxide layers on metals and alloys in gaseous and aqueous environments, adsorption of inorganic, organic and biomolecules, the mechanisms of corrosion of metals and alloys at the nanoscale, passivity, passivity breakdown and localized corrosion, initial stages of high temperature oxidation, and the applications of advanced surface analytical methods such as X-ray Photoelectron Spectroscopy, Scanning Tunnelling Microscopy and Spectroscopy, and Time-of-Flight Secondary Ions Mass Spectrometry.
Pr. Marcus has published over 450 papers in scientific journals, books and conference proceedings in the areas of surface chemistry and electrochemistry, surface analysis, corrosion science, and materials science, plus three books “Corrosion Mechanisms in Theory and Practice”, “Analytical Methods in Corrosion Science and Engineering”, and “Molecular Modeling of Corrosion Processes”. His h-index is 70, and number of citations 16807 (source: Google Scholar, September 2019). He has given over 120 invited lectures at International Conferences. He serves or served on the editorial board of five major journals in Electrochemistry and Corrosion: Electrochimica Acta, Corrosion Science, Materials and Corrosion, Corrosion Engineering, Science, and Technology, and Corrosion Reviews, and also Acta Sinica Metallurgica. Pr. Marcus has received a number of awards and honors, including the 2005 Uhlig Award from the Electrochemical Society, the 2008 Whitney Award from NACE International, the Cavallaro Medal of the European Federation of Corrosion in 2008, the U.R. Evans Award of the UK Institute of Corrosion in 2010, the Lee Hsun Award of the Institute of Metals Research of the Chinese Academy of Sciences in 2012. He was the D.B. Robinson Distinguished Speaker of the University of Alberta, Edmonton, Canada in 2013. He was awarded the European Corrosion Medal from the European Federation of Corrosion in 2015, and the Olin Palladium Award from the Electrochemical Society (USA) in 2017. He is an elected Fellow of the Electrochemical Society (2005) and of the International Society of Electrochemistry (2009).
Pr. Marcus was President of the European Federation of Corrosion from 2008 to 2012. He was Chair of the Electrochemical Materials Science Division of the International Society of Electrochemistry. He is currently Chair of the EFC Working Party on Surface Science and Mechanisms of Corrosion and Protection, Chair of the International Steering Committee for the European Conferences on Applications of Surface and Interface Analysis, Head of the Paris Office of the European Federation of Corrosion, and President of the French Corrosion Society (CEFRACOR).
Email: philippe.marcus@chimie-paristech.fr