[WB3] REBCO Mass Production II

5:31 PM - 5:46 PM JST(8:31 AM - 8:46 AM UTC)

[WB3-03] Advancements in Buffer Tape Production for 2G-HTS Applications at Faraday Factory Japan

Konstantin Vereshchagin¹、John Wifred Aclan¹、Alexey Mankevich¹、*Deniz Sanal¹、Marcel Mesko¹、Vladimir Vyatkin¹、Ivan Veshchunov¹、Hoa Dao¹、Alexander Molodyk¹、Valery Petrykin¹、Sergey Samoilenkov¹、Sergey Lee¹ (1. Faraday Factory Japan (Japan))

Keywords:

IBAD -MgO Buffer,Biaxially textured substrate,2G-HTS coated conductors,Thin Hastelloy substrate

Faraday Factory Japan (FFJ) is a global leader in the high-temperature superconductor (HTS) market, specializing in the production of second-generation (2G-HTS) tapes. FFJ is committed to reliably and cost-effectively delivering industrial-length REBCO coated conductors for use in power transmission and magnet systems. Achieving large-scale production depends on the quality of the bi-axially textured buffer substrate tape, which is crucial for defect tolerance, long-length uniformity, and ultimately determines both factory throughput and yield. As a result, we focus on the continuous improvement of a robust buffer process comprising Hastelloy /Al2O3 / Y2O3 / IBAD-MgO / epitaxial-MgO / LaMnO3 as the substrate for excellent REBCO superconductor deposition by Pulsed Laser Deposition (PLD) method. Our process development began with a first-generation, single-chamber IBAD (Ion Beam Assisted Deposition) system, which could produce buffer tapes at a maximum speed of 33 m/h using 60 um Hastelloy substrates, with single-piece lengths less than 500 meters. Today, our third-generation multichamber system operates at 210 m/h utilizing 30 um substrates, and can produce tapes up to 3 km in length. Scaling up the system and buffer manufacturing process presented several important challenges: Poor adhesion of oxide layers, Maintaining continuous stable and reliable equipment operation during prolonged times, Developing effective mechanical and tension control systems for 30 um tape, Ensuring uniformity of the top-layer biaxial texture. This presentation will outline our strategies and innovations in overcoming these challenges, particularly as we scaled up buffer tape manufacturing. We will discuss experiments and results with alternative buffer architectures, explain the principles behind our deposition control systems, and share 2G-HTS tapes performance, such as typical adhesion characteristics, in-plane texture quality and its distribution, effects of Hastelloy origin from different manufacturers, and etc. These advancements enable us to produce REBCO tapes with critical current values (Ic) of up to 1000 A/12 mm at 77 K. Through operational optimization and rigorous protocol control, reinforced by lean 5S practices, our current production line achieves an annual output of approximately 1000 kilometers of buffer substrate. Those principles will be used for next-generation IBAD equipment development aiming at production capacity of approximately 10000 kilometers per year.