Qi Li

6370405, Apr 9, 2002

Jul 29, 1997

08/902421

Qi Li - Marlborough MA
Peter R. Roberts - Groton MA
Peter D. Antaya - Sutton MA
Jeffrey M. Seuntjens - Singapore, SG
Steven Hancock - Worcester MA
Kenneth L. DeMoranville - Jefferson MA
Craig J. Christopherson - Worcester MA
Jennifer H. Garrant - Natick MA
Christopher A. Craven - Bedford MA

American Superconductor Corporation - Westborough MA

H01B 1202

505231, 505236, 505237, 505431, 505704, 1741251, 29599, 428702, 428930

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.

6370762, Apr 16, 2002

May 21, 1996

08/651688

Qi Li - Waltham MA
Theodore S. Greene - Seekonk MA
William J. Michels - Brookline MA
William L. Carter - Chelmsford MA

American Superconductor Corp. - Westborough MA

H01L 3924

29599, 505100, 505231

A reduced coefficient of friction, preferably created by ideal lubrication conditions, may advantageously be employed in the breakdown deformation of a precursor to a multifilamentary superconducting composite, particularly in combination with one or more high reduction breakdown drafts, to improve composite homogeneity and significantly increase the range of deformation conditions over which dimensional tolerances and J may be optimized. Precursor composites made by this method exhibit reduced microhardness variability and fewer and less serious transverse filament defects than composites made by prior art methods. 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 predetermined pressure and a coefficient of friction less than about 0. 2, preferably less than 0. 01, and preferably less than about 0.

6537689, Mar 25, 2003

Nov 26, 2001

09/995420

Suresh Annavarapu - Brookline MA
Martin W. Rupich - Framingham MA
Xiaoping Li - Westborough MA
Wei Zhang - Shrewsbury MA
Edward J. Siegal - Malden MA
Qi Li - Marlborough MA

American Superconductor Corporation - Westborough MA

C09K 1900

428701, 428930, 505237, 505238

The invention relates to multi-layer articles and methods of making such articles. The multi-layer superconductors can have one or more layers with an oriented termination plane. The methods include first conditioning the termination plane of an underlying layer, such as a buffer layer or a superconductor layer, then disposing a layer of material on the conditioned termination plane. The conditioned termination plane can be a high quality termination plane. Superconductor articles formed by these methods can exhibit relatively high critical current densities.

6555503, Apr 29, 2003

Sep 20, 2000

09/665882

Qi Li - Marlborough MA
Elliott D. Thompson - Coventry RI
Eric E. Hellstrom - Madison WI
David C. Larbalestier - Madison WI
Kenneth L. DeMoranville - Jefferson MA
Jeffrey A. Parrell - Roselle Park NJ
Jodi L. Reeves - Madison WI

American Superconductor Corporation - Westborough MA

H01B 1200

505432, 505433, 505501, 505822

A method of making an oxide superconductor article includes subjecting an oxide superconductor precursor to a texturing operation to orient grains of the oxide superconductor precursor to obtain a highly textured precursor; and converting the textured oxide superconducting precursor into an oxide superconductor, while simultaneously applying a force to the precursor which at least matches the expansion force experienced by the precursor during phase conversion to the oxide superconductor. The density and the degree of texture of the oxide superconductor precursor are retained during phase conversion. The constraining force may be applied isostatically.

6613270, Sep 2, 2003

May 30, 2000

09/583304

Qi Li - Marlborough MA
Lawrence J. Masur - Needham MA
Eric R. Podtburg - Natick MA
Ronald D. Parella - Holden MA
Martin W. Rupich - Framingham MA
Donald R. Parker - Randolph MA
William L. Carter - Chelmsford MA
William J. Rosati - Milford MA
Mark D. Teplitsky - Westborough MA

American Superconductor Corporation - Westborough MA

H01L 3900

264604, 264614, 264619, 505431, 505432, 29599

A novel process of the production and processing of high quality, high T 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. The precursor article is then heated at a second selected processing temperature in an inert atmosphere with a second selected oxygen partial pressure for a second selected time period, the second processing temperature, the second time period and the second oxygen partial pressure being cooperatively selected to form a dominant amount of an orthorhombic BSCCO phase in the reacted mixture. It may then be deformed to form an elongated precursor article of a desired texture; and thereafter heated at a third selected processing temperature in an inert atmosphere with a third selected oxygen partial pressure for a third selected time period, all cooperatively selected to convert at least a portion of the orthorhombic BSCCO phase to the final superconducting BSCCO material.

6620768, Sep 16, 2003

Sep 21, 2001

09/960189

Martin W. Rupich - Framingham MA
William L. Carter - Chelmsford MA
Qi Li - Westborough MA
Alexander Otto - Chelmsford MA
Gilbert Riley, Jr. - Marlborough MA

American Superconductor Corporation - Westborough MA

H01B 1200

505121, 505785

A novel process of the production and processing of high quality, high T (Bi,Pb)SCCO superconductors starts with fabrication of a precursor article including selected intermediate phases with desired chemical and structural properties. The precursor fabrication includes mixing raw powders with a desired ratio of Bi:Pb:Sr:Ca:Cu elements and reacting the mixture under different selected reaction conditions that form a precursor powder with a dominant (Bi, Pb)SCCO 2212 phase and without CaâPbâO phase, wherein the 2212 phase may be the orthorhombic 2212 phase. The precursor article is then subjected to optimized reaction and mechanical deformation processes that lead to a reaction induced texturing and deformation induced texturing, respectively. A heating process is used to convert the precursor powder to the 2223 phase and subsequent deformation and annealing processes may be used to form a substantially single phase, highly textured (Bi, Pb)SCCO 2223 superconductor with high Jc.

6694600, Feb 24, 2004

Nov 21, 2001

09/990953

Qi Li - Marlborough MA
Eric R. Podtburg - Natick MA
Patrick John Walsh - Newton MA
William L. Carter - Chelmsford MA
Martin W. Rupich - Framingham MA
Elliott Thompson - Coventry RI
Alexander Otto - Chelmsford MA

American Superconductor Corporation - Westborough MA

H01L 3924

29599, 505739, 505742, 505501

A method is described to prepare a highly textured oxide superconductor article in a single deformation-sinter process. A precursor article including a plurality of filaments comprising a precursor oxide having a dominant amount of a tetragonal BSCCO 2212 phase and a constraining member substantially surrounding each of the filaments is provided. Each of the filaments extends along the length of the article. The oxide article is subjected to a heat treatment at an oxygen partial pressure and temperature selected to convert a tetragonal BSCCO 2212 oxide into an orthorhombic BSCCO 2212 oxide and, thereafter, roll worked in a high reduction draft in a range of about 40% to 95% in thickness so that the filaments have a constraining dimension is substantially equivalent to a longest dimension of the oxide superconductor grains. The rolled article is sintered to obtain a BSCCO 2223 oxide superconductor.

6730410, May 4, 2004

Jul 14, 2000

09/616570

Leslie G. Fritzemeier - Mendon MA
Qi Li - Marlborough MA
Martin W. Rupich - Framingham MA
Elliott D. Thompson - Coventry RI
Edward J. Siegal - Malden MA
Cornelis Leo Hans Thieme - Westborough MA
Suresh Annavarapu - Brookline MA
Paul N. Arendt - Los Alamos NM
Stephen R. Foltyn - Los Alamos NM

Electronic Power Research Institute, Incorporated - Palo Alto CA
The Regents of the University of California - Oakland CA

B23B 1500

428469, 428697, 428699, 428701, 428702, 428930, 505236, 505237, 505238, 505239

Methods and articles for controlling the surface of an alloy substrate for deposition of an epitaxial layer. The invention includes the use of an intermediate layer to stabilize the substrate surface against oxidation for subsequent deposition of an epitaxial layer.