Chemical Compatibility Investigation of Thin-Film Oxygen Transport Membranes on Metallic Substrates
Abstract:Thin-film La0.58Sr0.4Co0.2Fe0.8O3− (LSCF58428) exhibits high oxygen permeability due to its high ionic and electronic conductivity. In order to increase the oxygen flux, a thin-film membrane on a structural substrate is beneficial. Different Ni-based alloys were studied as potential substrate materials. The chemical compositions and thermal expansion coefficients of Ni-based alloys were measured in this study. LSCF58428 layers were screen printed on Ni-based alloys and cofired at a high temperature in air. Microstructural and elemental analyses of samples were conducted using a scanning electron microscope and energy-dispersive X-ray spectroscope. X-ray diffraction was used to investigate the phase compositions. The Ni-based alloy, MCrAlY (with M=Ni, Co), with a high Al content showed better chemical compatibility with perovskite material at high temperatures than other Ni-based alloys. A reaction occurred between Sr in the perovskite and the alumina-based surface layer on MCrAlY. However, the reaction zone was found to be stable in mid-term annealing at 800°C in air. Hence, it is expected that this reaction will not prevent application as an oxygen transport membrane. Three different cofiring atmospheres were investigated. Air was found to be the only possible cofiring atmosphere.
Document Type: Research Article
Affiliations: 1: Institute of Energy and Climate – IEK1 Materials Synthesis and Processing, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany 2: Plansee SE, Innovation Services, 6600 Reutte, Austria
Publication date: 2011-03-01