Abstract: The present invention relates to the formation of whisker reinforced metal matrix composites in which complex boride or carbide whiskers are distributed throughout a metal, metal alloy, or intermetallic matrix. Exemplary complex boride whiskers include TiNbB, TiTaB, TiVB, NbHfB, and TiNbMoB. Exemplary complex carbide whiskers include TiNbC, TiVC, TiZrC, TiHfC, and TiTaC. A method for the in-situ formation of complex boride and complex carbide whiskers within metallic matrices is disclosed which involves reacting a mixture of individual complex ceramic-forming constituents in the presence of a metal to precipitate the desired complex ceramic whiskers in a metal matrix.

Abstract: A method is taught for the introduction of in-situ precipitated second phase materials, such as ceramic or intermetallic particles in a metal matrix, to a host metal. When an initial solvent-assisted reaction is utilized, metal-second phase composites having highly superior properties may be obtained. The invention may utilize the reaction of the second phase-forming constituents in a solvent metal medium to provide an intermediate material of finely-dispersed second phase particles in an intermediate metal matrix, in the form of a porous mass or sponge. Any desired loading of second phase in the final composite may be achieved by the admixture of this preformed intermediate material having a relatively high content of particulate material, with a molten host metal. Exemplary materials include titanium diboride in an aluminum matrix and titanium carbide in an aluminum matrix.

Abstract: This invention relates to a process for making in-situ precipitated second phase in a metal matrix which mixture is rapidly solidified to form a product. The invention also relates to a rapidly solidified product.

Abstract: This invention relates to ceramic-ceramic composites comprising a dispersion of ceramic particles in a ceramic matrix. The production of these composites involves the in-situ precipitation of ceramic particles in a solvent metal matrix and the conversion of the matrix to a ceramic by reacting it with a matrix reactive species. Exemplary ceramic dispersoids include TiB.sub.2, ZrB.sub.2, TiC and TiN. Exemplary ceramic matrices include AlN, Al.sub.2 O.sub.3 and SiO.sub.2.

Abstract: This invention relates to a composite material comprising an in-situ precipitated second phase in an intermetallic matrix, and to the process for making such a composite.

Abstract: This invention relates to a process for making composite materials involving the in-situ precipitation of second phase particles in a metal matrix, and the products thereof. The process involves the use of initial compound materials as a source of second phase-forming reactants in the production of metal-second phase composites. The composites produced may comprise distributions of either single or multiple second phase materials. Exemplary initial compound precursors include boron nitride, boron carbide, boron oxide, aluminum nitride, aluminum carbide, aluminum boride, iron oxide and copper oxide.

Abstract: A method is taught for the introduction of in-situ precipitated second phase materials, such as ceramic or intermetallic particles in a metal matrix, to a host metal. When an initial solvent-assisted reaction is utilized, metal-second phase composites having highly superior properties may be obtained. The invention may utilize the reaction of the second phase-forming constituents in a solvent metal medium to provide an intermediate material of finely-dispersed second phase particles in an intermediate metal matrix, in the form of a porous mass or sponge. Any desired loading of second phase in the final composite may be achieved by the admixture of this preformed intermediate material having a relatively high content of particulate material, with a molten host metal. Exemplary materials include titanium diboride in an aluminum matrix and titanium carbide in an aluminum matrix.

Abstract: A method for welding metal composite materials, including metal-ceramic composites, whereby a weld or filler material is prepared by the in-situ precipitation of ceramic in a metallic matrix. The filler material may comprise boride, carbide, oxide, nitride, silicide, etc., while the matrix metal may constitute a alloy or intermetallic of two or more metals. A strong bond is achieved when welding two conventional metals, a conventional metal and a metal-ceramic composite, or two metal-ceramic composites.

Abstract: A method is taught for the in-situ precipitation of ceramic materials in a metal matrix. By means of the solvent assisted reaction, metal-ceramic composites having highly superior properties may be obtained. The invention involves the reaction of the ceramic forming constituents in a metal solvent medium to provide very finely-dispersed ceramic particles in the metal matrix. Exemplary materials include titanium diboride in an aluminum matrix.

Abstract: Aluminum cells may be produced having cathode surfaces which are wetted by aluminum, said surfaces comprising Refractory Hard Materials in a non-graphitized carbon matrix. Such cells may utilize inclined or drained cathodes as well as non-consumable anodes.

Abstract: Aluminum cells may be produced having cathode surfaces which are wetted by aluminum, said surfaces comprising Refractory Hard Materials in a non-graphitized carbon matrix. Such cells may utilize inclined or drained cathodes as well as non-consumable anodes.

Abstract: This invention relates to an improved coating composition for application to aluminum cell cathodes, wherein said composition comprises a Refractory Hard Material, and a thermosetting resinous binder system.The resinous binder system is characterized by a char yield greater than 25 percent, while the coating composition exhibits expansion characteristics such as to adhere to a cathode block at temperatures up to and including those normally encountered in the operation of an aluminum cell. The ablation rate of the carbon system utilized is essentially equal to the combined wear and dissolution rate of the Refractory Hard Material in an aluminum cell environment.

Abstract: This invention relates to electrolytic reduction cells for aluminum production wherein tiles have been placed upon the cathode surfaces to improve the cell operation. These tiles have aluminum-wettable surfaces, which reduce electrical losses and increase cathode life. The tiles are produced from a mixture of refractory hard metal (RHM), a thermosetting resin, carbonaceous fillers and carbonaceous additives. The tiles are physically formed, polymerized and/or cross linked, and carbonized to form a tile which can be inserted into a cell. The tile may have the RHM homogeneously dispersed throughout the tile structure, or it may have the RHM concentrated in layered form.

Abstract: This invention relates to a method for the application of a coating composition containing Refractory Hard Material to a cathode substrate to prepare an aluminum wettable cathode surface.A mixture of Refractory Hard Material and carbon system is applied to a cathode substrate, cured and carbonized to a non-graphitized carbon matrix containing Refractory Hard Material, characterized by strong bonding of said matrix to said substrate and an ablation rate of said carbon matrix similar to the combined rate of wear and dissolution of the Refractory Hard Material.

Abstract: The invention relates to a method for protecting anode studs by coating the anode studs with an outermost surface layer of titanium diboride, zirconium diboride, titanium carbide, zirconium carbide, or mixtures thereof. The anode studs which are specifically to be protected in this instance are anode studs for electrolytic cells for the production of aluminum. The steel anode stud is conventionally subject to high corrosion rates due to the atmosphere in the aluminum furnace, and the industry has long sought means to protect this stud from corrosion without inhibiting electrical conductivity, while providing high temperature resistance to oxidation, and thermal shock resistance. It is also necessary that any coating applied to the steel anode stud be compatible with the carbon mass which is utilized as the anode per se. In accordance with the present invention, coatings of titanium diboride, zirconium diboride, titanium carbide, zirconium carbide, and mixtures thereof, have been found effective.

Abstract: Gunning mixes and other magnesia-based refractory compositions are disclosed which include up about to 10% by weight sulfamic acid as a binder. Sulfamic acid reacts readily with periclase grain and, when employed with boric acid and ceramic sintering aids forms an excellent binder system.

Abstract: An anode assembly for a fused bath cell. The steel stud has an intermediate coating between it and the carbon anode body of a corrosion resistant material of titanium diboride, zirconium diboride, titanium carbide or zirconium carbide. The coating may contain molybdenum disilicide.

Abstract: In an electrochemical cell, such as a fuel cell, the gas distribution layer, which is the layer of material disposed directly behind and contiguous with the catalyst layer, is made from gas porous open cell carbon foam. Vitreous carbon foam is preferred. Vitreous carbon foam is extremely corrision resistant to many of the very reactive chemicals which might be used as an electrolyte in a fuel cell, such as phosphoric acid. It also has low electrical resistivity, good thermal conductivity, and can be made very thin and inexpensively. Preferably the cell catalyst layer is applied directly to one surface of the foam layer.

Abstract: A ribbed electrode substrate for an electrochemical cell comprises a gas porous substrate having ribs of hydrophilic material extending across one side thereof. The other side of the substrate is substantially flat and may have a catalyst layer disposed thereon. In one embodiment a stack of fuel cells uses electrodes having these ribbed substrates. A flat, gas impermeable plate separates the electrode substrates of adjacent cells, the ribs of each substrate abutting opposite surfaces of the plate forming channels for carrying reactant gas across the cells. Electrolyte is stored in the ribs, which are hydrophilic. The electrolyte in the ribs moves to and from the electrolyte matrix of the cell by capillary action through the substrate.

Abstract: A method for fabricating porous carbon sheet material and in particular for fabricating porous carbon fuel cell electrode substrates comprises coating carbon fibers with a mixture of furfuryl alcohol and a catalyst which polymerizes furfuryl alcohol, forming the fibers into a mat or sheet of the desired size and thickness, heating the mat to polymerize the furfuryl alcohol and to cure the resin so formed, and further heating the mat to carbonize the resin.Phosphoric acid is the preferred polymerization catalyst when the sheet material is to be used as a fuel cell electrode substrate. The method produces electrode substrates which are highly porous yet strong and which are also corrosion resistant, thermally conductive and electrically conductive.