Abstract: A novel process of the production and processing of high quality, high Tc BSCCO or (Bi,Pb)SCCO superconductors starts with fabrication of a forming a bundle including a plurality of billets, each billet containing at least one filament comprising a dominant amount of an tetragonal BSCCO phase with selected intermediate phases, and substantially surrounded by a constraining metal. The bundle is thermomechanically consolidated to form a multifilamentary precursor article by applying pressure and heat to the bundle under conditions cooperatively selected to cause interdiffusion of said constraining metal at the interfaces between said metal and said filaments and substantially complete elimination of voids in said bundle, and the consolidation step is completed before any high strain longitudinal deformation is performed on the bundle.

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: A strongly-linked polycrystalline oxide superconductor article includes an oxide superconductor selected from the group consisting 124-type and 247-type oxide superconductors having fine, highly aligned oxide superconductor grains less than &mgr;m long a longest dimension. The oxide superconductor article has at least a 25% retention of critical current density in a 0.1 Tesla field.

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: A composite for preparation of an oxide superconductor includes a primary alloy phase of constituent elements of a desired oxide superconductor; and a secondary phase comprising copper, the secondary phase supported by the primary alloy phase. The composite may additionally include a matrix material for supporting the primary alloy phase and second phase disposed therein. The composite is oxidized to form an oxide superconductor composite.

Abstract: The combination of one or more high reduction drafts with controlled, low back tensions increases the range of deformation conditions over which dimensional tolerances and Je may be optimized. The method comprises the steps of: first, providing a precursor article comprising a metal matrix surrounding a plurality of filaments extending along the length of the article and comprising precursors to a desired superconducting ceramic; next, roll working the precursor article during a breakdown stage at a back tension less than the elastic to plastic transition threshold of the composite during at least one high reduction roll working draft, and, then, sintering the rolled article to obtain the desired superconducting ceramic. In a preferred embodiment, the rolling step further comprises rolling the article at a front tension less than the elastic to plastic transition threshold of the rolled, unsintered article.

Abstract: A novel process of the production and processing of high quality, high T.sub.c BSCCO or (Bi,Pb)SCCO superconductors starts with fabrication of a forming a bundle including a plurality of billets, each billet containing at least one filament comprising a dominant amount of an tetragonal BSCCO phase with selected intermediate phases, and substantially surrounded by a constraining metal. The bundle is thermomechanically consolidated to form a multifilamentary precursor article by applying pressure and heat to the bundle under conditions cooperatively selected to cause interdiffusion of said constraining metal at the interfaces between said metal and said filaments and substantially complete elimination of voids in said bundle, and the consolidation step is completed before any high strain longitudinal deformation is performed on the bundle.

Abstract: An unsegregated metal oxide/silver composite wire is provided having a plurality of metal oxide filaments disposed within a matrix comprising silver, wherein the filaments are comprised of at least copper, and an intermediate region comprising copper oxide and silver in contact with and surrounding each of the metal oxide filaments. The intermediate region has a thickness of no greater than three microns. Each of the metal oxide filaments extends continuously for the length of the wire, and each of the metal oxide filaments is separated from adjacent filaments by the matrix.

Abstract: A composite for preparation of an oxide superconductor includes a primary alloy phase of constituent elements of a desired oxide superconductor; and a secondary phase comprising copper, the secondary phase supported by the primary alloy phase. The composite may additionally include a matrix material for supporting the primary alloy phase and second phase disposed therein. The composite is oxidized to form an oxide superconductor composite.

Abstract: A strongly-linked polycrystalline oxide superconductor article includes an oxide superconductor selected from the group consisting 124-type and 247-type oxide superconductors having fine, highly aligned oxide superconductor grains less than 50 .mu.m along a longest dimension. The oxide superconductor article has at least a 25% retention of critical current density in a 0.1 Tesla field.

Abstract: A method for forming unsegregated metal oxide-silver composites includes preparing a precursor alloy comprising silver and precursor elements of a desired metal oxide and oxidizing the alloy under conditions of high oxygen activity selected to permit diffusion of oxygen into silver while significantly restricting the diffusion of the precursor elements into silver, such that oxidation of the precursor elements to the metal oxide occurs before diffusion of the metallic elements into silver. Further processing of the metal oxide composite affords an oxide superconducting composite with a highly unsegregated microstructure.

Abstract: The invention provides a process for production of silver-containing precursor alloys to oxide superconductors, said alloys having reduced amounts of intermetallics. Powders containing metallic elemental components of an oxide superconductor are high energy milled for a predetermined amount of time to increase homogeneity of the mixed metallic elemental components of the oxide superconductor. Silver is then high energy milled into the metallic components. The mixed silver and metallic elemental components of the oxide superconductor are compacted for the silver-containing superconductor precursor. The compacted powder is preferably hot worked at a temperature of at least 50% of the precursor alloy's melting temperature in degrees Kelvin.