Papers by Keyword: Alloy Interconnect

Abstract: The French Atomic Energy Commission has developed a High Temperature Electrolyzer having an original coaxial architecture. Important elements are spring-like interconnects which allow to cope with thermal dilatation. Specifications of these components are low-cost, long term electrical conductivity achieved by chemical and mechanical stability. Potential candidates are iron-based alloys on which thin silver-coating may be deposited. In this paper we study the interaction of such systems with a mixture of hot vapour and hydrogen that is representative of the electrolyzer environment. Oxidation kinetic is measured by thermogravimetry. The oxide layer composition and morphology of tested samples are then investigated using Energy Dispersive Spectroscopy (EDS) and Auger Electron Spectroscopy (AES). These analyses demonstrate that hydrogen content strongly impacts the oxidation mechanism.

Abstract: In the field of the ANR-PROD’HYGE project an original coaxial architecture for a High Temperature Electrolyser (French Atomic Energy Commission Patented) is studied which makes use of low-cost spring-like interconnects to cope with thermal dilatation. Components and materials used for this application must ensure high long-term chemical and mechanical stability which are investigated here. Oxidation resistance of EN1.4509 and CroFer22APUI iron based alloy as well as Haynes 230 nickel based alloy is investigated with thermogravimetric analysis (TGA) in humid conditions, with or without mixing with hydrogen. Experiments reveal that oxidation kinetics is increased by 30% volume of hydrogen in moisture. Oxide layer composition and morphology are then investigated using Energy Dispersive Spectroscopy (EDS), and Auger Electron Spectroscopy (AES). Preliminary tensile tests are performed at room temperature showing embrittlement due to rough oxide layer, and CroFer22APU softening due to grain growth at elevated temperature.