| abstract |
A method of producing porous membrane structure for fuel cells by means of Fe—Cr alloy powders and oxides of Fe—Cr alloy powders and oxides of Fe, Cr, Ni or Co is characterised by said powders being mixed so that Fe/(Fe+Cr) is in the range of 50-90%, a paste of said powders being produced by means of solvents, surfactants or binders, pore formers possibly being added in order to obtain porosity, and if the product produced by means of the suspension is to be dense, sintering aids may be added as appropriate sites, the suspension being tape-cast, extruded, rolled or the like and heat treated or the like and heat treated in an oxygen containing atmosphere for burn out of organic components and sintered in highly reducing atmosphere for reducing to Fe, Ni, Co and possibly also to Cr so that oxides of Fe, Ni, Co and Cr are at least partly reduced to metallic states reacting with the Fe—Cr powder. As a result the requirements to TEC corrosion resistance etc. are fulfilled. The temperature ramp and Po 2 is varied so as to control the shrinkage profile. |