Investigation of Hybrid Wires Combining Superconductive MgB2 and Ultra-conductive Graphene/Cu sheath

Abstract

In our study, hybrid wires with ultra-conductive Graphene/Copper(GCu) sheath and superconducting MgB2 core were produced and experimentally examined. Cu tubes with outer/inner diameters of 15/12 mm were first coated with multi-layered graphene by chemical vapour deposition (CVD) method. Then, the ultra-conductive G/Cu tubes were filled with Mg+2B powder and they were gradually drawn into wires with a diameter of 1.94 mm. According the analysis results, the graphene coating process was successfully completed and the hybrid wires were produced by achieving MgB2 superconducting phase formation after annealing at 650∘C for 1 h. In this study, a graphene-coated copper tube with a CVD process was used for the first time to manufacture a superconducting wire. The ampacity value of industrial G/Cu sample has been improved in hybrid wires about 75% despite Cu exposed to mechanical deformations throughout the wire production process after graphene coating.