Process for producing a superconducting wire having a chevrel phases

Abstract

The invention relates to a process for producing a superconducting wire, using, e.g., Chevrel phases as superconductors, in particular PbMo.sub.6 S.sub.8. Until now, it was not possible to produce superconducting wires from such materials in a technically usable quality. According to the process of the invention, the superconducting Chevrel phase is loaded vacuum-tight into a molybdenum shell and the unit is advantageously sealed in another jacket made of steel. The powdery superconducting phase has an average grain size of less than 1 .mu.m. For shaping the superconducting wire, the unit is extruded in a first process step at temperatures between 1000.degree. and 1600.degree. C. and reduced in cross section in excess of 1:10, and subsequently further treated in a plurality of process steps by additional extruding and/or hot drawing. Superconducting wires produced as specified above exhibit values for the critical quantities such as current bearing capacity, critical current density and limit values of the magnetic field that conform to those of the technically sophisticated superconductors of type II, or surpass the values of the latter type in individual instances. At the same time, it was possible to wind such wires to form coils without impairing the superconducting values due to the brittleness of the Chevrel phases.