Research in the field of high temperature oxidation has received Carnot "Materials for energies of the future" certification. The industrial and social challenge is to make sure that systems working at high temperature have maximum durability, which is synonymous with economic savings, coupled with prospects of sustainable development by optimising recycling times. The scientific goal is to gain a better understanding of the parameters and mechanisms that condition such durability. Our work has concerned thin FeCrAl alloy strip used for catalytic, zirconium alloys (collaboration with CEA-Saclay), Ni-based alloys (collaboration with AREVA NP), the metal interconnectors of SOFCs (Franco-Thai programme and support from APERAM). Research on SOFC interconnectors has expanded through the signing of two successive Franco-Thai partnership agreements (PHC) on this topic, which highlight the behaviour of interconnectors in the presence of gas biofuels on the anode side. It is also worth noting that the group is the leader partner in the ANR PSEUDO (Semi-conducting properties study of thin metallic oxide layers). This project aims to improve lifetime of metal alloys used in extreme conditions, mostly in power generation systems (solar, thermal, nuclear power plants, HTE, SOFC…).
From the fundamental standpoint, we have demonstrated experimentally beyond any doubt that the growth direction of thermal chromium oxide on stainless steel is reversed owing to the mobile hydroxylated chemical species in Cr2O3. We have also become a member of the new CNRS "EVAPECOHT" research group concerned with the "steam" aspects of high-temperature oxidation phenomena. Within this community, we are responsible for carrying out detailed mechanistic studies.
About the research on the stoechiometry of chromia
Recent research in our group in coll. with Univ. of Lorraine (France) has demonstrated that chromia stoichiometry at high temperature could be accurately estimated in function of oxygen partial pressure (see above fig.).This new result offers some promising possibility to improve the life time of chromia forming alloys at high temperature.