Flux pinning for in situ Nb/sub 3/Sn superconducting wire

Journal Article · Mon Aug 01 04:00:00 EDT 1983 · Acta Metall.; (United States)

DOI:https://doi.org/10.1016/0001-6160(83)90185-2· OSTI ID:6215759

Verhoeven, J D; Finnemore, D K; Gibson, E D; Ostenson, J E; Sue, J J

Critical currents and upper critical fields have been evaluated in order to determine which aspects of filament morphology are most important for flux pinning. Wire specimens were prepared with a wide range of Nb/sub 3/Sn filament sizes as controlled by the as-cast dendrite size, the degree of wire drawing and the degree of filament coarsening. Tape specimens were examined as a function of orientation in the magnetic field. The Nb/sub 3/Sn filament and grain morphology were examined with SEM and TEM techniques. In all cases the pinning force was found to follow an h /SUP 1/2/ (1-h)/sup 2/ dependence where h is the reduced magnetic field, H/H /SUB c2/ and the data consistently yielded parallel lines on a Kramer plot. Neither the perfect lattice shear model of Kramer nor the surface pinning model of Dew-Hughes adequately describe in situ data. Analysis and the Nb/sub 3/Sn filament and grain morphology indicates that flux pinning is not dominated by either the Nb/sub 3/Sn/Bronze interfaces or the Nb/sub 3/Sn grain boundaries, but is probably due to a combination of pinning at both interfaces.

• Research Organization: Ames Laboratory, USDOE, Department of Materials Science and Engineering
• OSTI ID: 6215759
• Journal Information: Acta Metall.; (United States), Journal Name: Acta Metall.; (United States) Vol. 31:8; ISSN AMETA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360101 -- Metals & Alloys-- Preparation & Fabrication
360102* -- Metals & Alloys-- Structure & Phase Studies
656102 -- Solid State Physics-- Superconductivity-- Acoustic
Electronic
Magnetic
Optical
& Thermal Phenomena-- (-1987)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALLOYS
BRONZE
COPPER ALLOYS
COPPER BASE ALLOYS
CRYSTAL LATTICES
CRYSTAL STRUCTURE
DRAWING
FABRICATION
FILAMENTS
GRAIN BOUNDARIES
GRAIN ORIENTATION
INTERFACES
MAGNETIC FLUX
MATERIALS WORKING
MATHEMATICAL MODELS
METALLURGY
MICROSTRUCTURE
MORPHOLOGY
NIOBIUM ALLOYS
ORIENTATION
PHYSICAL METALLURGY
SHEAR
SUPERCONDUCTING WIRES
SUPERCONDUCTORS
TIN ALLOYS
WIRES