Axial Tension and Overcurrent Study on a Type of Mass-Producible Joint for ReBCO Coated Conductors

Abstract

Given the limited length of ReBCO coated conductors (CCs), a large number of joints is necessary in high-temperature superconducting (HTS) applications. The quality of joints largely determines the stability of the HTS applications, because joints are usually weaker than ReBCO CCs themselves concerning mechanical and electrical characteristics. To address this problem, a novel type of CC joint, which employs a fabrication process similar to CC lamination, is developed (named after “lamination joint” for convenience). In this paper, the behaviors of the lamination joints under axial tension loads and dc/ac overcurrent are investigated. Single fully laminated CCs and joints fabricated by a conventional soldering method are also studied for comparison. The lamination joints exhibit similar critical axial tensile forces (around 700 N) to the single fully laminated CCs, which are much larger than that of the conventional soldering joints. Moreover, overcurrent tests show that the lamination joints have smaller possibilities to burn out than the single fully laminated CCs. Moreover, the lamination joints are much more stable in quality and are mass producible since they are automatically fabricated by a lamination system. Furthermore, a joint resistance of several <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{n}\Omega$</tex-math></inline-formula> can be achieved by simply extending the splicing length to several meters.