Abstract: An elongated current limiting composite material comprising one or more high-temperature superconductor filaments and a second electrically conductive member, which may include a sheath of high bulk resistivity surrounding the filament. The current limiter exhibits dissipation in the range of 0.05-0.5 V/cm at currents of 3-10 times the operating current, thereby minimizing fault currents and improving recovery capability.

Abstract: A superconducting article having a high bulk sheath resistivity, and methods of manufacture of such an article. High-temperature superconductor filaments are disposed in a ductile matrix comprising a high silver content. The matrix is then coated with a solute and heated to a temperature high enough to allow the solute to diffuse into the matrix, but not high enough to allow substantive degradation or poisoning of the superconductor. After diffusion and cooling, the matrix comprises a silver alloy having a higher bulk resistivity than the pure silver.

Abstract: A multifilamentary superconductor composite having a high fill factor is formed from a plurality of stacked monofilament precursor elements, each of which includes a low density superconductor precursor monofilament. The precursor elements all have substantially the same dimensions and characteristics, and are stacked in a rectilinear configuration and consolidated to provide a multifilamentary precursor composite. The composite is thereafter thermomechanically processed to provide a superconductor composite in which each monofilament is less than about 50 microns thick.

Abstract: The invention features high performing composite superconducting oxide articles that can be produced from OPIT precursors substantially without poisoning the superconductor. In general, the superconducting oxide is substantially surrounded by a matrix material. The matrix material contains a first constraining material including a noble metal and a second metal. The second metal is a relatively reducing metal which lowers the overall oxygen activity of the matrix material and the article at a precursor process point prior to oxidation of the second metal. The second metal is substantially converted to a metal oxide dispersed in the matrix during or prior to a first phase conversion heat treatment but after formation of the composite, creating an ODS matrix.

Abstract: An improvement in a process of preparing a composite high temperature oxide superconductive wire is provided and involves conducting at least one cross-sectional reduction step in the processing preparation of the wire at sub-ambient temperatures.

Abstract: A multifilamentary superconductor composite having a high fill factor is formed from a plurality of stacked monofilament precursor elements, each of which includes a low density superconductor precursor monofilament. The precursor elements all have substantially the same dimensions and characteristics, and are stacked in a rectilinear configuration and consolidated to provide a multifilamentary precursor composite. The composite is thereafter thermomechanically processed to provide a superconductor composite in which each monofilament is less than about 50 microns thick.

Abstract: The invention features high performing composite superconducting oxide articles that can be produced from OPIT precursors substantially without poisoning the superconductor. In general, the superconducting oxide is substantially surrounded by a matrix material. The matrix material contains a first constraining material including a noble metal and a second metal. The second metal is a relatively reducing metal which lowers the overall oxygen activity of the matrix material and the article at a precursor process point prior to oxidation of the second metal. The second metal is substantially converted to a metal oxide dispersed in the matrix during or prior to a first phase conversion heat treatment but after formation of the composite, creating an ODS matrix.

Abstract: The invention features high performing composite superconducting oxide articles that can be produced from OPIT precursors substantially without poisoning the superconductor. In general, the superconducting oxide is substantially surrounded by a matrix material. The matrix material contains a first constraining material including a noble metal and a second metal. The second metal is a relatively reducing metal which lowers the overall oxygen activity of the matrix material and the article at a precursor process point prior to oxidation of the second metal. The second metal is substantially converted to a metal oxide dispersed in the matrix during or prior to a first phase conversion heat treatment but after formation of the composite, creating an ODS matrix.

Abstract: An improvement in a process of preparing a composite high temperature oxide superconductive wire is provided and involves conducting at least one cross-sectional reduction step in the processing preparation of the wire at sub-ambient temperatures.

Abstract: A superconducting article having a high bulk sheath resistivity, and methods of manufacture of such an article. High-temperature superconductor filaments are disposed in a ductile matrix comprising a high silver content. The matrix is then coated with a solute and heated to a temperature high enough to allow the solute to diffuse into the matrix, but not high enough to allow substantive degradation or poisoning of the superconductor. After diffusion and cooling, the matrix comprises a silver alloy having a higher bulk resistivity than the pure silver.

Abstract: A cask for storing and transporting highly radioactive materials includes an inner shell and a number of layers of depleted uranium wire wound on the inner shell to create a radioactive shield against emanation of radioactivity from the material stored within the inner shell.

Abstract: Techniques for producing fine metal powder are described, including producing droplets of molten metal to be formed into a powder, providing an environment including a substance specifically introduced for combining with the droplets, and submitting the droplets to the environment for combining the introduced substance with the droplet metal to form at least a partial coating on the powder including the introduced substance.

Abstract: Pieces of metal are joined with silver material in a two-stage heating process. In one application, a brazed porous coating of metal particles on a metal substrate of a device is formed by interposing a silver material between the substrate and the particles, and placing the particles onto the substrate. The device is heated to a first temperature slightly below the melting point of the silver material, then briefly heated to a second temperature above 1100.degree. C. to rapidly melt the silver material to wet the particles and substrate and to generate alloying among the silver material, the particles, and the substrate. The device is allowed to cool to solidify the alloy and unite the particles and substrate to form a porous coating on the device. Also disclosed are a prosthetic device having a metal shaft for insertion into a bone canal, and a porous coating of metal particles brazed to the metal shaft by a silver material.

Abstract: A method and apparatus for producing fine metal powder. The method includes the steps of forming a centrifugally maintained annulus of a liquified gas quench medium, forming molten metal drops within the eye of the annulus, urging the drops into the quench medium to solidify the drops, and boiling away the quench medium to leave behind clean, unentrained metal powder. The apparatus includes a drum for containing a liquified gas quench medium, means for adding liquified gas to the inside of the drum, and means for rotating the drum to form an annulus of quench medium. The apparatus further includes means for forming molten metal to be made into powder, and means disposed along the longitudinal axis of the drum and within the eye of the annulus for creating molten metal drops. The molten metal drops are then urged into the quench medium to solidify them into a powder, and the quench medium is boiled away to leave behind clean, unentrained metal powder.

Abstract: Pieces of metal are joined with silver material in a two-stage heating process. In one application, a brazed porous coating of metal particles on a metal substrate of a device is formed by interposing a silver material between the substrate and the particles, and placing the particles onto the substrate. The device is heated to a first temperature slightly below the melting point of the silver material, then briefly heated to a second temperature above 1100.degree. C. to rapidly melt the silver material to wet the particles and substrate and to generate alloying among the silver material, the particles, and the substrate. The device is allowed to cool to solidify the alloy and unite the particles and substrate to form a porous coating on the device. Also disclosed are a prosthetic device having a metal shaft for insertion into a bone canal, and a porous coating of metal particles brazed to the metal shaft by a silver material.

Abstract: An apparatus for manufacturing solidified metallic forms from levitated molten metal including a levitation conduit having an interior surface for accommodating the metal to be levitated, and a device for introducing the metal to the levitation conduit. Induction coils induce a moving magnetic field in the levitation conduit to levitate the metal upwardly through the conduit, and to maintain the outer surface of the levitated metal while molten out of pressured contact with the interior surface of the levitation conduit. The molten metal output is provided to a chamber in which a device re-forms the molten metal output and solidifies it.

Abstract: A rotary electrode apparatus for producing metal powders including a chamber for maintaining a controlled atmosphere. A first electrode is mounted in the chamber and a second consumable disc electrode is mounted in the chamber confronting the first electrode. An electric arc is struck between the first electrode and a circumferential portion of the disc electrode in order to melt the circumferential portion. The disc electrode is rotated at sufficient speed to enable melting of the circumferential portion of the disc and spinning off of melted portions of the disk.

Abstract: A collimated hole structure formed by constricting a plurality of tubular elements each provided with a core for supporting the tubular element during the constricting operation. The bundle of elements is constricted to a point where the elements effectively fuse into a substantially monolithic body. The cores are then removed, leaving a plurality of extremely small diameter, generally parallel passages in a solid body. The tubular elements may be arranged in any desired array, and thus the passages may be provided similarly in any desired array. The passages may have high aspect ratios and may be closely juxtaposed. In one illustrative application, the collimated hole structure is provided with dielectric film and utilized as an anode portion of an electrolytic capacitor. In another illustrative application, the collimated hole structure is utilized as a tip for a drilling device.