Patent ID: 6289576
Filing Date: 2001-09-18
Classification: H01L,Y10S

Abstract:
In the process of producing a wireform superconductive article of predefined length and diameter, which is a length of at least about 1 kilometer and a diameter of less than about 1 mm, by the process that comprises:A. disposing a high temperature superconductive composition in a sleeve, comprising a metallic composition comprising silver, to form a filled sintering sleeve, wherein said sintering sleeve has an outside diameter substantially greater than about 1 mm and wherein said metallic composition is permeable to oxygen and is sufficiently ductile to be drawable;B. subjecting said filled sintering sleeve to a sufficient number of diameter reducing steps in a wire drawing process to form a drawn, filled sintering sleeve having said predefined length and diameter, wherein as a consequence of said wire drawing process said sintering sleeve is cold worked and therefore becomes less ductile and harder;C. heat treating said drawn sintering sleeve in effective contact with of oxygen at a temperature and for a time sufficient to sinter said superconductive composition;the improvement, whereby enabling the formation of substantially endless superconducting wire of said predefined length and diameter, that comprises;D. at least substantially surrounding said sintering sleeve with a first drawing sleeve, comprising a metal of greater tensile strength and higher hardness than said sintering sleeve, to form a first composite structure comprising said superconductive composition as a core, said sintering sleeve about said core, and said drawing sleeve about said sintering sleeve;wherein said drawing sleeve has the ability to take up a substantial proportion, that is a greater portion than said sintering sleeve, of the tensile forces exerted on the first composite structure during a subsequent diameter reducing wire drawing thereof;E. subjecting said first composite structure to a sufficient number of diameter reducing steps in a wire drawing process to form a first drawn, substantially endless wire form product, wherein said drawn sintering sleeve has a diameter that is greater than said predefined wire form diameter, and wherein, as a consequence of said drawing, at least one of said sintering sleeve and/or said drawing sleeve will have become sufficiently hardened, embrittled and reduced in ductility, to substantially interfere with a continued wire drawing process;F. removing said first drawing sleeve under conditions sufficient to not substantially adversely affect said sintering sleeve of said first substantially endless drawn wire form product;G. annealing said first drawn sintering sleeve surrounding said superconducting composition, under conditions sufficient to increase the ductility of said sintering sleeve without substantially affecting said superconductive core material, to form a first annealed sintering sleeve;H. at least substantially surrounding said first annealed sintering sleeve with a second drawing sleeve, comprising a metal of higher tensile strength and greater hardness than said first annealed sintering sleeve, to form a second composite structure;I. subjecting said second composite structure to a sufficient number of diameter reducing steps in a second diameter reducing wire drawing process to form a second substantially endless wire form product, comprising a drawn sintering sleeve having said predetermined diameter;J. removing said second drawing sleeve to form a second drawn sintering sleeve, wherein said removal of said second drawing sleeve is conducted under condition that will not substantially adversely affect said sintering sleeve and/or said superconductive core material; andK. heat treating said drawn sintering sleeve in effective contact with of oxygen at a temperature and for a time sufficient to sinter said superconductive core composition, to thereby form a substantially endless wire form product comprising a sintered superconductive core.