Removing the Metal Layer From REBCO-Coated Conductors and Constructing Oxygen Channels via a Laser-Electrochemical Hybrid Process

The selective removal of metallic stabilizers is a key segment for both the fabrication of superconducting joints and the surface characterization of the superconducting layer in REBCO-coated conductors (CCs). However, the REBCO is highly susceptible to chemical corrosion, and conventional wet etching techniques often induce irreversible degradation due to delamination of the superconducting layer. To address this challenge, this study presents a non-destructive electrochemical etching process. We successfully validated the application of this etching method on REBCO CCs fabricated using three distinct superconducting layer deposition techniques, achieving a single-pass etching length of up to 30 millimeters while fully preserving superconducting properties. Moreover, a hybrid process combining electrochemical etching and laser cutting was employed to successfully construct oxygen channels on the surface of the superconducting layer. This method not only produced a 20mm-long etched sample containing three oxygen channels but also achieved a critical current with virtually no degradation.