Continuous electropolishing technique for long-length Hastelloy C-276 tape

Preparation of the second-generation high-temperature superconducting tape by ion beam-assisted deposition (IBAD) requires a flat metal substrate. In this work, the electrochemical polishing of long-length Hastelloy C-276 alloy was studied, and its process parameters, characterized roughness and other properties were investigated. A 10-meter-long Hastelloy C-276 alloy was prepared by electrochemical polishing. The following optimized processing parameters are obtained: temperature of 45 °C, current density of 0.439 A·cm−2 and polishing time of 60 s. The average roughness value (Ra) of the surface is less than 5 nm (5 μm × 5 μm), which was characterized by atomic force microscopy. This value satisfies the requirements for the further preparation of transition-layer pair by the IBAD technology route.