| 摘要 |
1247832 Super-conductors SIEMENS AG 25 June 1970 [25 June 1969] 30973/70 Headings H1A A5 A4B and A4D A super-conductor cable comprises a tube having a strip form conductor assembly fixed flat against a lateral external face, the assembly containing wires of super-conductor material twisted about a longitudinal axis of the assembly and embedded in normally conductive material. As shown, Fig. la, a stabilized super-conductor strip 2 comprising Nb-Ti wires 5 embedded in a Cu matrix 4 is soldered using a Pb-Sn alloy to one face of a Cu tube 1. The wires 5 are twisted about the axis of the strip and this is achieved by twisting an oversize strip containing parallel conductors and working by drawing and rolling to a smaller rectangular cross-section. A second stabilized super-conductor strip may be secured to the opposite face of the tube. The cable may be strengthened by securing a strip of non-magnetic steel or of a Cu-Be alloy to the face of a Cu tube opposite to that to which the super-conductor strip is secured, Fig. 2 (not shown), or by making the tube of one of these materials, Fig. 3 (not shown). In a second embodiment, Fig. 4 (not shown), twelve stabilized super-conductor bars are assembled so that they are transposed in turn (Roebel bars) and secured in a frame attached to one face of a normal metal tube. The bars may be insulated from one another and from the frame by layers of lacquer or may be soldered together. A plurality of parallel bars each containing twisted super-conductor wires may be used instead of the transposed bars. For A.C. purposes the superconductor wires may be stabilized with a resistive metal e.g. CU-Ni alloy, and the tube may be of a low electrical conductivity high tensile strength material. The cable may be assembled by joining lengths of tube together by hard soldering into sleeves, joining lengths of the super-conductor strip together by cold pressure butt welding, and securing the strip to the tube by soldering or by electron beam welding. The super-conductor material may also be a Nb-Zr alloy and the stabilizing metal and tube may also be of Al. The solder may also be In or a Sn-Ag alloy and when the normal metal is Al ultrasonic soldering may be utilized.
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