The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 21, 1993
Filed:
Mar. 10, 1988
Tapan K Gupta, Monroeville, PA (US);
George J Bich, Pittsburgh, PA (US);
William N Lawless, Westerville, OH (US);
United States of America as represented by the Secretary of the Air Force, Washington, DC (US);
Abstract
The composite insulation coating consists of a mixture of glass and ceramic oxide(s), coated onto a wire by conventional wire enameling techniques followed by heat treatment at 600.degree.-850.degree. C. The enamel when initially applied, the 'green' coat slurry, consists of four components: (1) the glass, (2) an inorganic filler (ceramic oxide powder, (3) an organic binder and (4) an organic solvent. The glasses can be selected from several commercial glasses (Corning 7570 and 7050) as well as Westinghouse glasses A-508, M 3072 and M 3073. None of these glasses contain lead or boron, allowing for nuclear applications. Suitable ceramic fillers are alumina, and the CeramPhysics, Inc. ceramics SC1C and SC1A. Organic binder materials and solvents are used. It is preferable that a copper wire to be coated with Ni, Inconel or Cr prior to coating with the subject insulation. For superconductors, the brittle nature of Nb.sub.3 Sn wire and the high reaction temperature (.about.700.degree. C.) required to form it preclude the use of standard organic insulation systems. The inorganic insulation with SC1C and SC1A ceramics, characterized by unusually high specific heats and thermal conductivities at cryogenic temperatures, offers the opportunity of providing increased enthalpy stabilization in a superconducting winding. The glass and ceramic is chosen so that the vitrification temperature of the composite coincides with the reaction temperature of 600.degree.-800 .degree. C. The most successful glasses meeting this criterion are A-508 and M3072.