Influence of metallurgical factors on superconducting current densities in ''bronze-processed'' Nb/sub 3/Sn multifilamentary wires

Journal Article · Sat Jan 01 00:00:00 EST 1983 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.331699· OSTI ID:6535857

Okuda, S; Suenaga, M; Sabatini, R L

A number of metallurgical factors influencing superconducting properties, primarily critical current densities, of bronze-processed Nb/sub 3/Sn multifilamentary wires were examined for a set of wires in which the ratio of bronze to Nb, R, varied from 2.0 to 3.7. The morphology and the size of the Nb/sub 3/Sn grains were found to be strongly influenced by R and the temperature at which the compound was formed. A qualitative model for the growth of the compound layer is proposed accounting for the microstructural variations in the wires. The critical-current density J/sub c/ of the wires was the highest for those heat treated at 725 /sup 0/C for 192 h, and was essentially independent of R. The highest J/sub c/ was also found in the wires with approx.7-..mu..m filaments, compared with those with approx.3- and approx.15-..mu..m filaments. The decreases in J/sub c/ with the reduction of the filament size to 3 ..mu..m was correlated with the spread in the distribution of the filament sizes. By examination of the present and the previous data on J/sub c/ of multifilamentary Nb/sub 3/Sn wires, it is concluded that values of J/sub c/ of approx.800 A/mm/sup 2/ at 10 T and approx.500 A/mm/sup 2/ at 12 T can be easily achieved in bronze-processed wires without an undue amount of effort in fabrication, but to achieve significantly higher values (approx.1200 A/mm/sup 2/ or higher at 10 T) may require extensive quality control in the manufacturing of these composite wires.

• Research Organization: Division of Metallurgy and Materials Science, Brookhaven National Laboratory, Upton, New York 11973
• OSTI ID: 6535857
• Journal Information: J. Appl. Phys.; (United States), Vol. 54:1, Issue 1
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
NIOBIUM COMPOUNDS
CRITICAL CURRENT
SUPERCONDUCTING WIRES
METALLURGY
TIN COMPOUNDS
CURRENT DENSITY
EXPERIMENTAL DATA
FILAMENTS
GRAIN SIZE
HEAT TREATMENTS
MATHEMATICAL MODELS
MORPHOLOGY
TEMPERATURE DEPENDENCE
VERY HIGH TEMPERATURE
CRYSTAL STRUCTURE
CURRENTS
DATA
ELECTRIC CURRENTS
INFORMATION
MICROSTRUCTURE
NUMERICAL DATA
SIZE
TRANSITION ELEMENT COMPOUNDS
WIRES
420201* - Engineering- Cryogenic Equipment & Devices