OREANDA-NEWS. Sumitomo Electric Industries, Ltd. has developed an extra-high-strength superconductor "DI-BSCCO™ Type HT-NX" by substantially increasing the tensile strength of the company's high-strength bismuth high-temperature superconductor from 250-270 MPa to over 400 MPa. Sales commenced in April 2015.

For the R&D project on this superconductor, "Development of a High-Strength Bi-2223 Conductor," Sumitomo Electric received the 19th Superconductivity Science and Technology Award from the Society of Non-Traditional Technology.

The extra-high-strength bismuth high-temperature superconductor exhibits 50% to 60% higher tensile strength than conventional high-strength bismuth high-temperature superconductors. This implies that the extra-high-strength superconductor withstands an increased electromagnetic force to be suitable for use in large magnets and ultrahigh magnetic fields up to over 20 tesla, which could not be achieved with conventional high-strength superconductors.

In addition to meeting the needs associated with ultrahigh magnetic fields and high electromagnetic forces, the extra-high-strength superconductor enables the downsizing of various devices due to its higher current density than conventional copper wires and metallic superconductors. Moreover, its high superconductivity improves magnetic field accuracy and stability, and is therefore expected to make devices highly sensitive.

Meanwhile, the newly developed superconductor is approximately 30% smaller in critical bending diameter than the previous conductors. Consequently, it can also be used in coils with smaller bending diameter.

Future tasks include developing a mass-production system for bismuth high-temperature superconductors of 200 A or higher critical current to provide our customers with more user friendly superconductors.

The scientific achievements of this superconductor for practical applications have gained high academic recognition. Sumitomo Electric received the Award on Superconductivity Science and Technology from the Society of Non-Traditional Technology.

Specifications for conventional high-strength and extra-high-strength superconductor

DI-BSCCO Type HT series - Specifications
  High Strength Extra high strength
  Type HT-SS Type HT-CA Type HT-NX
Average Width 4.5 mm 4.5 mm 4.5 mm
Average thickness 0.29 mm 0.34 mm 0.31 mm
Reinforcement
(thickness)		 Stainless steel
(20 ?m)		 Copper alloy
(50 ?m )		 Nickel alloy
(30 ?m )
Unit length Up to 500m
Critical current: Ic
(77K, self field)		 (170 A,) 180 A, 190 A, 200 A
Critical tension* (RT) 230 N ** 280 N ** 410 N **
Critical strength* (77K) 270 MPa ** 250 MPa ** 400 MPa **
Critical strain* (77K) 0.4% ** 0.3% ** 0.5% **
Critical double bending diameter* (RT) 60 mm** 60 mm** 40 mm**

 

In 2004, Sumitomo Electric released a bismuth high-temperature superconductor as an industrial product. Since then, the product has been selected by numerous customers for use in new applications and also as a replacement for existing copper wires and metallic superconductors. However, for use by an increasing number of customers, the bismuth high-temperature superconductor has had hurdles to surmount, major ones of which were critical current and critical tensile strength.

In the leading-edge fields of basic science such as chemistry and medical care, demand is growing for a higher magnetic field generation in research equipment, analyzers, and diagnostic systems using magnetic fields. Likewise, demand is growing steadily for smaller, more accurate, and more sensitive devices.