New perspectives on flux pinning in niobium-titanium composite superconductors

Journal Article · Thu Nov 01 04:00:00 EST 1984 · Acta Metall.; (United States)

DOI:https://doi.org/10.1016/0001-6160(84)90168-8· OSTI ID:6388190

Labalestier, D C; West, A W

The critical current densities of a Nb-46.5 wt% Ti multifilamentary composite given various combinations of heat treatments have been measured. Transmission electron microscopy has been performed on the wires at various stages in the fabrication so that the changes in flux pinning behavior produced by processing can be related to the microstructure. Models are proposed to explain the mechanisms of flux pinning due to the microstructures produced by final size heat treatments and by heat treatments followed by additional drawing. The microstructures produced by a single heat treatment at final size are sufficiently simple that a grain boundary flux pinning force can be derived. This pinning force is found to vary by more than a factor of three depending on the heat treatment. This result is also found to hold for the earlier data on Neal et al. We conclude that the flux pinning of Nb-Ti alloys is not well-described by an inverse grain size dependence except under very restricted circumstances.

• Research Organization: Applied Superconductivity Center, University of Wisconsin-Madison, Madison, WI
• OSTI ID: 6388190
• Journal Information: Acta Metall.; (United States), Journal Name: Acta Metall.; (United States) Vol. 32:11; ISSN AMETA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360601 -- Other Materials-- Preparation & Manufacture
420201* -- Engineering-- Cryogenic Equipment & Devices
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALLOYS
COMPOSITE MATERIALS
CRYSTAL STRUCTURE
DRAWING
FABRICATION
GRAIN SIZE
HEAT TREATMENTS
MAGNETIC FLUX
MATERIALS
MATERIALS WORKING
MATHEMATICAL MODELS
MEASURING METHODS
METALLURGY
MICROSTRUCTURE
NIOBIUM ALLOYS
NIOBIUM BASE ALLOYS
PHYSICAL METALLURGY
SIZE
SUPERCONDUCTING COMPOSITES
SUPERCONDUCTING WIRES
TEMPERATURE EFFECTS
TITANIUM ALLOYS
WIRES