Frederick Elsner

US Patent:

52848256, Feb 8, 1994

Filed:

Aug 17, 1992

Appl. No.:

7/901546

Inventors:

Richard B. Stephens - Del Mar CA
Frederick H. Elsner - Carlsbad CA

Assignee:

General Atomics - San Diego CA

International Classification:

B05D 302
B05D 512

US Classification:

505 1

Abstract:

A superconducting structure is provided comprising a substrate, a superconductor coating supported by the substrate and a diffusion barrier positioned between the superconductor coating and the substrate to inhibit diffusion of contaminants from the substrate to the superconductor coating. The coating is a ceramic oxide having superconducting properties. The diffusion barrier may likewise be a ceramic oxide, but differs in its specific composition to provide it with a peritectic decomposition temperature greater than the superconductor coating. Accordingly, the diffusion barrier exhibits substantially lower atomic mobility than the superconductor coating during manufacture of the superconducting structure, thereby preventing contamination of the coating by the substrate.

US Patent:

51496844, Sep 22, 1992

Filed:

Apr 9, 1991

Appl. No.:

7/682552

Inventors:

Lawrence D. Woolf - Carlsbad CA
Frederick H. Elsner - Cardiff CA
Clyde H. Shearer - Santee CA

Assignee:

General Atomics - San Diego CA

International Classification:

C01D 1102
C01D 1100
C01G 302

US Classification:

505 1

Abstract:

A process for preparing a superconductor-coated substrate including calcining a mixture of powdered yttrium or rare earth oxide (R), barium carbonate and copper oxide in a controlled atmosphere and in accordance with a predetermined temperature profile to form a superconductor powder having a stoichiometric ratio of R-Ba-Cu of approximately 1-2-3. The melting transition width of the resulting powder is relatively narrow, such that the melting onset temperature is above the high temperatures advantageously used to sinter the powder on the substrate.

US Patent:

51186632, Jun 2, 1992

Filed:

Sep 21, 1990

Appl. No.:

7/586450

Inventors:

Lawrence D. Woolf - Carlsbad CA
Michael V. Fisher - San Diego CA
William A. Raggio - Del Mar CA
Frederick H. Elsner - Carlsbad CA

Assignee:

General Atomics - San Diego CA

International Classification:

H01B 1200

US Classification:

505 1

Abstract:

A method and apparatus for manufacturing a superconductor wire has a wire take-up spool and a feed speed control spool. A wire substrate is taken from the feed speed control spool and onto the take-up spool as the wire take-up spool is rotated. The wire passes through a container which holds a diffusion barrier material, where the diffusion barrier material is electrophoretically deposited onto the wire substrate and subsequently sintered. The wire is also passed through a container which holds a superconductor material suspended in solution, and a layer of the superconductor material is electrophoretically deposited onto the diffusion barrier. The grains of the superconductor layer are then magnetically aligned and sintered. Also, a silver coating is electrophoretically deposited onto the superconductor layer and sintered. A diffusion bonding inhibitor material is then applied to the silver coating.

US Patent:

50473891, Sep 10, 1991

Filed:

Oct 31, 1988

Appl. No.:

7/265827

Inventors:

Lawrence D. Woolf - Carlsbad CA
Frederick H. Elsner - Cardiff CA
William A. Raggio - Del Mar CA

Assignee:

General Atomics - San Diego CA

International Classification:

B32B 300

US Classification:

505 1

Abstract:

A substrate for supporting a ceramic superconductor comprises a metallic base member having a constituent oxide former which establishes an oxide layer on the surface of the substrate. A layer of ceramic superconducting material covers the substrate with the oxide layer between the metallic base member and the ceramic superconductor layer to inhibit the interdiffusion of respective constituent elements between the metallic base member and the ceramic layer. For applications requiring the transmission of electrical current through the ceramic layer over relatively extensive distances, the substrate can be formed as a wire.

US Patent:

54683580, Nov 21, 1995

Filed:

Jul 6, 1993

Appl. No.:

8/088075

Inventors:

Tihiro Ohkawa - La Jolla CA
Frederick H. Elsner - Carlsbad CA

Assignee:

General Atomics - San Diego CA

International Classification:

C25D 1302

US Classification:

2041815

Abstract:

Methods for making fiber-reinforced carbon, ceramic or metal matrix composites using electrophoretic infiltration of an array or preform of electrically insulating fibers positioned adjacent a target electrode in an appropriate liquid slurry. The slurry contains a dispersion of micron- or submicron-sized particles, usually of elemental or ceramic materials, which are suitably electrically charged in the slurry, employing a surfactant if necessary. Application of an appropriate voltage causes charged particles to migrate toward the target electrode following a path that causes them to infiltrate the interstices of the fiber array which is usually formed of woven or aligned tows of minute fibers about 5 to 15 microns in diameter. The particles initially deposit on the electrode with subsequent particles aggregating on top of those particles, the process continuing to form a growth front of deposited material growing away from the electrode surface. The resultant deposit of aggregating particles grows through the interstices of the fibrous preform from one surface of the preform to the other, filling voids with matrix material.

US Patent:

51643600, Nov 17, 1992

Filed:

May 24, 1990

Appl. No.:

7/528683

Inventors:

Lawrence D. Woolf - Carlsbad CA
Frederick H. Elsner - Cardiff CA
William A. Raggio - Del Mar CA

Assignee:

General Atomics - San Diego CA

International Classification:

B32B 900

US Classification:

505 1

Abstract:

A ceramic superconductor comprises a substantially nonmagnetic preannealed nickel-based alloy substrate which supports a ceramic superconductor. The substrate may include aluminum to strengthen the substrate, make it less magnetic and enhance its chemical compatibility with the ceramic superconductor. The ceramic is formed on the substrate by sintering superconductor grains at temperatures above 1000. degree. C. to enhance densification of the ceramic.

US Patent:

51235862, Jun 23, 1992

Filed:

Sep 21, 1990

Appl. No.:

7/586768

Inventors:

Lawrence D. Woolf - Carlsbad CA
Clyde H. Shearer - Santee CA
Frederick H. Elsner - Cardiff CA

Assignee:

General Atomics - San Diego CA

International Classification:

B23K 100
B23K 119
B23K10316

US Classification:

228124

Abstract:

A process for joining ceramic superconductor fibers with a channel to fabricate a superconductor wire includes feeding the fibers into the channel and continuously dispensing a flowable solder paste into the channel over the fibers. The combination of channel, fibers and solder paste is then subjected to a rapid rise in temperature which sequentially activates the flux in the solder paste and then melts the solder. After the workpiece is cooled and the separated flux has been removed, a superconductor wire has been fabricated.

US Patent:

50732404, Dec 17, 1991

Filed:

Sep 21, 1990

Appl. No.:

7/586001

Inventors:

William A. Raggio - Del Mar CA
Frederick H. Elsner - Cardiff CA
Lawrence D. Woolf - Carlsbad CA

Assignee:

General Atomics - San Diego CA

International Classification:

C25D 1300

US Classification:

2041815

Abstract:

A process for depositing a silver coating onto a superconductor involves placing the superconductor into an alcohol solution, preferably octanol, which contains silver particles. Each silver particle is coated with a layer of oleic acid. An electrode, preferably made of silver, is also disposed in the anhydrous solution. A direct current voltage is then established on the electrode, which causes the silver particles to plate onto the superconductor. After electrophoresis, the now-plated superconductor is heated to nine hundred degrees centigrade (900. degree. C. ) for approximately one (1) minute.