Characterization of Nb-Ti superconductors with artificial pinning structures

Conference · Fri Jun 01 00:00:00 EDT 1990

OSTI ID:5196025

Dietderich, D R; Scanlan, R M

A series of multifilamentary APC Nb-Ti superconductors have been made with Nb added as a normal second phase to provide flux pinning centers. Two compositions, 12.5% vol % and 25 vol % Nb in Nb-Ti, have fabricated into multifilamentary composites using two different fabrication methods. One method used hot isostatic compaction and hot extrusion thoughout the processing. The other method (bundle-and-draw process) discontinued all hot processing at an intermediate level. While the J{sub c} values of the bundle-and-draw wires are quite promising, the critical current of the extruded wires appears to be limited by poor uniformity of the filament cross-sectional area along the conductor length. The large values of the index of the resistive transition and small filament standard-deviation-to-average area ratios observed in the wires produced by the bundle-and-draw process suggest extrinsic factors have little effect on J{sub c}. The variation in J{sub c} as the wire diameter is reduced appears to be most strongly affected by intrinsic factors: Nb distribution and pinning strength. The final filament microstructure and Nb spacing are shown to be difficult to calculate, e.g., the mean Nb spacing near the final wire size may be {1/2} to 1/3 that of the calculated value. 5 refs., 5 figs.

• Research Organization: Lawrence Berkeley Lab., CA (United States)
• Sponsoring Organization: USDOE; USDOE, Washington, DC (United States)
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 5196025
• Report Number(s): LBL-30063; SC-MAG-322; CONF-910635-16; ON: DE92000862
• Resource Relation: Conference: Cryogenic engineering conference and international cryogenic materials conference, Huntsville, AL (United States), 11-14 Jun 1991
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
NIOBIUM ALLOYS
CRITICAL CURRENT
TITANIUM ALLOYS
ELECTRON MICROSCOPY
MICROSTRUCTURE
SUPERCONDUCTING WIRES
ALLOYS
CRYSTAL STRUCTURE
CURRENTS
ELECTRIC CURRENTS
MICROSCOPY
WIRES
360104* - Metals & Alloys- Physical Properties
426001 - Engineering- Superconducting Devices & Circuits- (1990-)