GB1437871A - Preparation of a composite electrical conductor including an intermetallic superconductor compound - Google Patents

Abstract

1437871 Making superconductive conductors SIEMENS AG 26 July 1974 [1 Aug 1973] 33234/74 Heading B3A [Also in Divisions C7 and H1] A composite electrical conductor including an intermetallic superconductor compound, e.g. Nb 3 Sn or V 3 Ga, is made from a structure comprising a first element of the superconductor compound in contact with a carrier metal, the structure being heated in a vacuum of not over 10<SP>-2</SP> Torr or a non-reacting gas at a pressure not over 500 Torr in a vapour of the other element or elements of the superconductor in the presence of a melt of the said other element or elements. The first element is preferably a core or cores of Nb or V clad in a Ag, Cu or Cu-Ag matrix which may contain a proportion of the other element, e.g. 0-8À5 atomic per cent of Sn or 0-23 atomic per cent of Ga. Alternatively the Nb or V cores may be formed as Nb or V coatings or sheaths on Cu, Ag or Cu-Ag cores and these composite cores are sheathed in the carrier metal, the sheathed structure being cold drawn to the required size, sealed and heated in a container with a source of Sn or Ga melt and exposed to the vapour in vacuum or gas atmosphere of A or He. For Nb 3 Sn the structure is heated at 600-850‹ C. and for V 3 Ga at 600- 950‹ C. The structure in the form of wire is preferably treated while wound around a stave wheel having ceramic staves.