Magnetohydrodynamic electrode

Claim 1

A composite electrode for use in a magnetohydrodynamic generator comprising: a refractory ceramic matrix containing 10 to 50 volume percent of a continuous metal reinforcement which is an electrically conductive nonferromagnetic, oxidation-resistant metal or alloy melting above 1000° C., the metal being selected from the group consisting of niobium, hafnium, tantalum, molybdenum, and alloys of niobium-zirconium, hafnium-tantalum, nickel-chromium and nickel-molybdenum, the form of the reinforcement being selected from the group consisting of a sintered fiber mat, an open-pore foamed metal and a three-dimensional woven wire fabric, and the refractory ceramic matrix being selected from the group consisting of stabilized zirconium oxide, stabilized hafnium oxide, iron-doped spinel, chromium-doped spinel, yttrium oxide and strontium-doped lanthanum chromite; the electrode having a top surface, a bottom surface and parallel side walls; an electrically and thermally conductive intermediate attachment plate fastened to the bottom surface of the electrode in electrical contact with the metal reinforcement, the plate having edges in line with the side walls; the side walls of the electrode and edges of the atachment plate being coated with a layer of refractory ceramic electrical insulating material; and a layer of unreinforced refractory ceramic on the top surface of the electrode.