Revolutionary Weld Technique Unlocks Superconductor Potential

A new welding technique for high-temperature superconductors is adding to the range of practical applications for these materials.

High-temperature superconductors, which lose electrical resistance when cooled with liquid nitrogen, were discovered in the late 1980s. They hold the potential for generating more efficient magnetic fields and transmitting electricity without loss to resistance.

Some applications are in use, but most ideas require large components. Researchers have been unable to make large high-performance superconducting structures that carry current uniformly and have found it difficult to join smaller sections together without interfering with electrical flow.

Now Argonne materials scientists have developed a way to weld high-temperature superconductors, creating strong bonds that preserve their crystal structures across the joint. The welded unit operates at the temperature of liquid nitrogen, acts as a single entity, and can be made large enough for high-energy-density motors, high-current wire or cable, energy storage devices, fault current limiters and current leads.

“This innovation is an essential and long-awaited, key to widespread use of high-temperature superconductors in the electric-power industry,” said Boyd Veal, one of the project’s principal investigators.

The process bonds pieces of yttrium-based boron-copper-oxide, YBCO, using a layer of thulium-based boron-copper-oxide, TmBCO. As the joint cools after heating, the YBCO seeds the TmBCO layer, creating a weld that is mechanically strong and carries current as well as undisturbed bulk YBCO.

For more information please contact Richard Greb at 630-252-5565

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