Protective coating for substrates that are subjected to high temperatures and method for producing said coating

• Main Authors: ZAHID MOHSINE, TIETZ FRANK, SHEMET VLADIMIR
• Format: Patent
• Language: English
• Published: 11.05.2006
• Subjects: BASIC ELECTRIC ELEMENTS; CHEMICAL COMPOSITION OF GLASSES, GLAZES, OR VITREOUSENAMELS; CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; ELECTRICITY; GLASS; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; JOINING GLASS TO GLASS OR OTHER MATERIALS; LAYERED PRODUCTS; LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT ORNON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM; METALLURGY; MINERAL OR SLAG WOOL; PERFORMING OPERATIONS; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS,MINERALS OR SLAGS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; TRANSPORTING

As a rule, chromium-oxide forming materials for high temperatures, in particular chromium-based alloys or chromium-rich alloys based on iron (ferritic steel), are used as interconnector materials that are subjected to high temperatures. At SOFC operating temperatures, said material group forms a chromium-based oxidic top coating, which has the advantage of preventing rapid oxidation damage, but also the disadvantage of continuing to react, forming Cr(VI) compounds. Said volatile compounds react regularly with the cathode material, producing the negative effect of impairing the oxygen reduction. The invention relates to a gas-tight protective coating, devoid of chromium, for chromium-oxide forming substrates, such as for example typical interconnector materials, said coating regularly preventing the evaporation of chromium VI compounds during SOFC operating conditions. The invention also relates to a simple method for producing said gas-tight protective coating that is devoid of chromium.