Abstract: A container system including a vessel for holding a thixotropic semi-solid aluminum alloy slurry during its processing as a billet and an ejection system for cleanly discharging the processed thixotropic semi-solid aluminum billet. The crucible is preferably formed from a chemically and thermally stable material (such as graphite or a ceramic). The crucible defines a mixing volume. The crucible ejection mechanism may include a movable bottom portion mounted on a piston or may include a solenoid coil for inducing an electromotive force in the electrically conducting billet for urging it from the crucible. During processing, a molten aluminum alloy precursor is transferred into the crucible and vigorously stirred and controlledly cooled to form a thixotropic semi-solid billet. Once the billet is formed, the ejection mechanism is activated to discharge the billet from the crucible. The billet is discharged onto a shot sleeve and immediately placed in a mold and molded into a desired form.

Abstract: Ion texturing methods and articles are disclosed.

Abstract: In general terms, the present invention relates to an electrical power transmission system using superconductors which is compatible with conventional transmission systems. In a first aspect, the present invention relates to a method for installing in an electrical power transmission system a connection using a coaxial superconducting cable, comprising the following steps: determining the reactance of a conventional cable suitable for the said connection; installing the coaxial superconducting cable; increasing the reactance of the coaxial superconducting cable, in such a way that the reactance of the superconducting cable is substantially equal to the reactance of the conventional cable. In particular, the step of increasing the reactance of the coaxial superconducting cable comprises the step of connecting in series with the coaxial superconducting cable an inductive element, preferably made from a superconducting material.

Abstract: A laminate article comprises a substrate and a biaxially textured (RExA(1−x))2O2−(x/2) buffer layer over the substrate, wherein 0<x≦0.70 and RE is selected from the group consisting of La, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. A is selected from the group consisting of Zr+4, Ce+4, Sn+4, and Hf+4. The (RExA(1−x))2O2−(x/2) buffer layer can be deposited using sol-gel or metal-organic decomposition. The laminate article can include a layer of YBCO over the (RExA(1−x))2O2−(x/2) buffer layer. A layer of CeO2 between the YBCO layer and the (RExA(1−x))2O2−(x/2) buffer layer can also be include. Further included can be a layer of YSZ between the CeO2 layer and the (RExA(1−x))2O2−(x/2) buffer layer. The substrate can be a biaxially textured metal, such as nickel. A method of forming the laminate article is also disclosed.

Abstract: The invention provides an apparatus for supplying power to superconducting loads includes a current source, a cryogenic region (e.g., a cryogenic chamber), a first switching device in series between the current source and a superconducting load, and a second switching device in parallel with the superconducting load. The switching devices are arranged so that, when the first is closed and the second is open, recharging current is supplied to the superconducting load. The second switching device serves as a shunt. When it is closed and the first is open, current recirculates through the persistent (or partially persistent) superconducting load. The invention also provides a superconducting magnet incorporating such a power supply.

Abstract: A method of producing ceramic superconducting materials such as YBa.sub.2 Cu.sub.3 O.sub.x includes blending together starting materials for the superconducting material. The blend of starting materials are formed into a layer and sintered at a temperature above the peritectic temperature for the superconducting material. Prior to sintering, the starting materials for the superconducting material may be unreacted. The starting materials may also be partially reacted prior to sintering by calcining for a period of time at a temperature which does not result in full reaction of the starting materials to the chemical composition of the desired superconducting material.

Abstract: The invention provides an apparatus for supplying power to superconducting loads includes a current source, a cryogenic region (e.g., a cryogenic chamber), a first switching device in series between the current source and a superconducting load, and a second switching device in parallel with the superconducting load. The switching devices are arranged so that, when the first is closed and the second is open, recharging current is supplied to the superconducting load. The second switching device serves as a shunt. When it is closed and the first is open, current recirculates through the persistent (or partially persistent) superconducting load. The invention also provides a superconducting magnet incorporating such a power supply.

Abstract: A superconductor comprising a compound of the formula (II):R.sub.1+x Ba.sub.2-x Cu.sub.3 O.sub.7-y1 (II)wherein not less than 40% of a crystal of the superconductor shows phase separation, and at (temperature, magnetic field) of (77?K!, O?T!) and (77?K!, 4?T!), a critical current density is not less than 10,000 A/cm.sup.2, which is obtained by heating a precursor which is a solid solution of the formula (I):R.sub.1+x Ba.sub.2-x Cu.sub.3 O.sub.7-y (I)wherein not more than 10% of a crystal of the solid solution shows phase separation, so that phase separation is formed in the crystals at a phase separation temperature, and introducing oxygen; and a superconductor comprising a compound of the formula (II):R.sub.1+x Ba.sub.2-x Cu.sub.3 O.sub.7-y1 (II)wherein not more than 10% of a crystal of the superconductor shows phase separation, and in a magnetic field of not less than 1?T! at a constant temperature of 77?K!, a critical current density is less than 10,000 A/cm.sup.

Abstract: High T.sub.c superconducting magnetic shields are provided, together with a method of fabricating such shields, wherein the shields exhibit very high critical applied magnetic field values of at least about 50 Gauss at 77 K. In fabrication procedures, a particulate superconducting ceramic oxide (24) (e.g., thallium 2223) is placed within an uniaxial die assembly (10) and subjected to compression while the die is heated via an external heating jacket (26). After formation of a self-sustaining body (24a), the die (10) is additionally heated via the jacket (26). External heating of the die (10) with the superconducting material therein reduces internal stresses within the shield body.

Abstract: Composites, and a method for preparing composites, are provided. The composites have a plurality of domains of inorganic compounds of from 0.4 to 1000 nanometers on the surfaces of a support material. The domains may contain one or more inorganic compounds, the ratio of which can be controlled by the process.

Abstract: A superconductor material having a current density, J, of from about 30,000 to about 85,000 amps/cm.sup.2 at zero magnetic field and 77.degree. K is disclosed. The 123 superconductor, of the formula L.sub.1 Ba.sub.2 Cu.sub.3 O.sub.6 +.delta. wherein L is preferably yttrium, is capable of entrapping sufficiently high magnetic fields and exhibits a low microwave surface resistance. The process of preparing the superconductor comprises compacting the bulk product, L.sub.1 Ba.sub.2 Cu.sub.3 O, and then sintering the reaction product at a temperature between about 40.degree. C. to about 90.degree. C. below its melting point, i.e., for Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.6 +.delta. at a temperature of approximately 940.degree. C. The composition is then heated in a preheated chamber maintained at approximately 1090.degree. C. to about 1,200.degree. C. (approximately 1,100.degree. C. for Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.6 +.delta.

Abstract: Superconducting materials and methods of forming superconducting materials are disclosed. Highly oxidized superconductors are heated at a relatively high temperature so as to release oxygen, which migrates out of the material, and form a non-superconducting phase which does not diffuse out of grains of the material. The material is then reoxidized at a lower temperature, leaving the non-superconducting inclusions inside a superconducting phase. The non-superconducting inclusions act as pinning centers in the superconductor, increasing the critical current thereof.

Abstract: To produce a high-temperature superconductor of the composition Bi.sub.2 (Sr,Ca).sub.3 Cu.sub.2 O.sub.8+x having a strontium to calcium ratio of 5:1 to 2:1 and a value of x between 0 and 2, the oxides and/or carbonates of bismuth, strontium, calcium and copper are vigorously mixed in a stoichiometric ratio. The mixture is heated at a temperature of 870.degree. to 1100.degree. C. until a homogeneous melt is obtained. The melt is poured into mold and allowed to solidify in them. The cast bodies removed from the molds are annealed for 6 to 30 hours at 780.degree. to 850.degree. C. Finally, the annealed cast bodies are treated for at least 6 hours at temperatures of 600.degree. to 820.degree. C. in an oxygen atmosphere. The cast bodies can be converted into shaped bodies of the desired sizes by mechanical processes before they are annealed. The shape and size of the shaped bodies may also be determined by the shape and dimensioning of the mold used in producing the cast bodies.

Abstract: A superconducting switch is composed of anisotropic magnetic material. The switch has a first superconducting section, a variable resistive section and a second superconducting section. An external magnetic field is applied so that the first and second superconducting sections remain superconducting and the resistive section changes resistance when the magnetic field applied exceeds the critical field of the variable resistance section. The different critical field regions are achieved by exploiting the natural critical field anisotropy of the ceramic superconductors (a previously unobserved phenomena in metal superconductors). By making the different sections with different orientations they will exhibit different critical field valves for a given direction of applied fields. The state of the switch is changed by either increasing or decreasing the external magnetic field about the critical field value of the resistive section of the switch.

Abstract: The disclosed superconductive material has a characteristic in accordance with which electrical resistance disappears at a temperature of at least more than the boiling point of 20.3.degree. K. (-252.7.degree. C.) of liquid hydrogen and relates to La-Ba-Cu-O series superconductive material.Said superconductive material consists essentially of a composition having the formula(La.sub.1-x M.sub.x).sub.2 CuO.sub.4-x/2wherein, M=Ba or Ba(Sr, Ca) and x=0.04.about.0.20 as a main body, wherein the material has a K.sub.2 NiF.sub.4 crystal structure.