Zagirov N.N., Cand. Sc. (Engineering), Assistant Professor of FGAOU VO «Sib erian Federal University»;
Loginov Yu.N., Dr. Sc. (Engineering), Professor of FGAOU VO «B.N. Eltsin Ural Federal University», Leading Research Scientist of FGBUN «M.N. Mikheev Institute of Metal Physics» of the Ural Branch of the Russian Academy of Sciences;
Nadol’ko A.S., Senior Lecturer of FGAOU VO «Siberian Federal University»
Changes in the structural state of copper wire with oxide inclusions during resistance welding
The method of cable waste recycling based on solid phase treatment without the use of melts is discussed. This technology was employed in the laboratory environment to obtain welding copper wire. The results of using copper wire as
a welding material are described. Consideration is given to the weld zone structure and the achieved level of the mechanical properties of the wire. The phenomenon of fibrous structure smoothing under thermal exposure in the weld zone is described.
copper recycling; pressing; drawing; thermal treatment; composite structure; resistance welding.
Loparev V.V., Cand. Sc. (Engineering), Head of Laboratory, OJSC VNIIKP;
On new GOST 839–2019 «Non-insulated conductors for overhead power lines. Specifications»
Kovalev I.A., Cand. Sc. (Engineering), Leading Research Scientist;
Kruglov S.L., Dr. Sc. (Engineering), Leading Research Scientist;
Makarenko M.N., Deputy Head of Laboratory;
Polyakov A.V., Junior Research Scientist;
Shutova D.I., Cand. Sc. (Physics and Mathematics), Research Scientist; National Research Centre «Kurchatov Institute»
Effect of copper coating on dynamic modes of current carrying elements made of REBCO tapes
High temperature superconducting (HTS) tapes are now used in AC superconducting transmission cable lines, current leads for accelerators, superconducting energy storage systems, windings of electrical machines,
etc. Development of high current caring elements made of multiple HTS tapes is required for large scale superconducting applications. HTS REBCO stacks soft-soldered for thermal and mechanical stability along the entire length were proposed recently. Investigation of these REBCO conductors and determination of their operational characteristics is an important practical issue.
In this work we experimentally investigate the current caring capacity of HTS stacks made of 1 or 5 REBCO tapes in either protective (1.5 μm) or stabilizing (20 μm) copper coatings at current ramp rates up to 400 kA/s in comparison with those made of bare REBCO tapes. Experimental ring-samples with joints were charged in external magnetic field generated by multy-layer outer solenoid at magnetic field ramp rates up to 10 T/s. The acceptable ramp rates were determined for the 7 samples (4 samples based on SuperPower tapes and 3 samples made of SuperOx tapes). An excellent thermal stability of REBCO conductors in liquid nitrogen was experimentally confirmed. The current caring capacity of the samples was maintained at 70 % to 95 % of their initial critical current with no transitions to the normal state at current ramp rates 200–300 kA/s corresponding to 5.5–8.5 T/s magnetic field ramp rates.
high-temperature superconductivity (HTSC); High-temperature second generation superconducting tapes (HTSC-2G); stabilizing layer, soldered tapes.