摘要:
A method is disclosed for producing a protective coating on a chromium oxide-forming substrate, which comprises the steps of: (a) applying on the chromium-oxide-forming substrate having at least one alloying addition selected from the group consisting of manganese, magnesium, and vanadium, a coating consisting essentially of at least one spinel-forming element selected from the group consisting of cobalt, nickel, copper and vanadium, (b) forming a chromium oxide layer at the substrate/applied coating interface, and (c) at a temperature of 500° C. to 1000° C. causing the diffusion of the at least one alloying addition through the chromium oxide layer and forming a compound thereof with the at least one spinel-forming element diffusing from the applied coating and forming between the chromium oxide layer on the substrate and the applied coating, a uniform, compact, adherent chromium-free gas-tight spinel layer.
摘要:
In a method of producing on the surface of a component which consists of a titanium alloy or an intermetallic phase on the basis of titanium, a protective layer (according to the formula Ti5,0−xAgx+yAl3,0−yO2), a mixture of Ti powder and TiO2 powder, which has been sintered, is applied to the surfaces of the component or, if the titanium alloy includes 40-60 at % Al, a coating of silver is applied to the component and the component is then heat treated at 500 to 900° C. to form the protective layer on its surfaces.
摘要:
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.
摘要:
A high temperature material which consists of a chromium oxide forming iron alloy including: a) 12 to 28 wt % chromium, b) 0.01 to 0.4 wt % La, c) 0.2 to 1.0 wt % Mn, d) 0.05 to 0.4 wt % Ti, e) less than 0.2 wt % Si, f) less than 0.2 wt % Al, wherein, at temperatures of 700° C. to 950° C., the high temperature material is capable of forming a Mn Cr2O4 spinel phase. At a temperature of 700° C. to 950° on Mn, Cr2O4 the spinel phase formed protects a body, such as spark plug electrodes and other electrodes.