Effects of strain on the superconducting properties of niobium-tin conductors
Thesis/Dissertation
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OSTI ID:5659869
Typical Nb/sub 3/Sn multifilamentary superconducting composites produced by the bronze diffusion process have repetitive fiber elements of niobium embedded in a bronze matrix, with a Nb/sub 3/Sn reaction zone serving as the interfacial layer between the two. Clusters of these units are surrounded by tin diffusion inhibitors, such as tantalum, and placed inside a second external copper matrix. The strain degradation of the critical current density has been both analytically and experimentally investigted in an inversion of this configuration. The new geometry consists of bronze filament cores inside of niobium tubes, with the usual Nb/sub 3/Sn interface. Since the niobium acts as a diffusion barrier, copper can be directly utilized as the embedding matrix, eliminating the motivation for tantalum addition. Analytic results were obtained from a computer program (MAXIMSUPER) which evaluates the three-dimensional strain fields on the Nb/sub 3/Sn zones in a cylindrical repeateing element of the composite due to both residual (thermal contraction) and applied axial loading. Investigations were performed to ascertain additional information on the connection between the cubic to tetragonal martensitic phase transformation and the phenomenon of superconductivity in Nb/sub 3/Sn. Results indicate that the martensitic phase transition temperature T/sub m/, increases with increasing compressive strains. Critical parameters, such as H/sub c2/ and T/sub c/ are thought to vary according to a two-level state model which expresses the Nb/sub 3/Sn cubic-to-tetragonal, martensitic-phase transformation as being strain sensitive. Good agreement between the MAXIMSUPEr predictions and experimental results indicates that the program may be suitable for superconducting composite design applications.
- Research Organization:
- Washington Univ., Seattle (USA)
- OSTI ID:
- 5659869
- Country of Publication:
- United States
- Language:
- English
Similar Records
MAXIMSUPER: a computer program to assist in the design of multifilamentary superconducting composites. [Nb/sub 3/Sn]
Final report to Lawrence Livermore Laboratory, University of California, under Contract No. 3237609, dated August 31, 1978
Final report to Lawrence Livermore Laboratory, University of California, under contract no. 3237609 dated August 31, 1978
Conference
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Tue Jul 03 00:00:00 EDT 1979
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OSTI ID:6061533
Final report to Lawrence Livermore Laboratory, University of California, under Contract No. 3237609, dated August 31, 1978
Technical Report
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Mon Dec 31 23:00:00 EST 1979
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OSTI ID:5522517
Final report to Lawrence Livermore Laboratory, University of California, under contract no. 3237609 dated August 31, 1978
Technical Report
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Mon Dec 31 23:00:00 EST 1979
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OSTI ID:6245134
Related Subjects
36 MATERIALS SCIENCE
360103* -- Metals & Alloys-- Mechanical Properties
360104 -- Metals & Alloys-- Physical Properties
ALLOYS
COMPRESSION
COMPUTER CODES
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
INTERMETALLIC COMPOUNDS
NIOBIUM ALLOYS
NIOBIUM BASE ALLOYS
PHYSICAL PROPERTIES
STRAINS
SUPERCONDUCTIVITY
TIN ALLOYS
360103* -- Metals & Alloys-- Mechanical Properties
360104 -- Metals & Alloys-- Physical Properties
ALLOYS
COMPRESSION
COMPUTER CODES
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
INTERMETALLIC COMPOUNDS
NIOBIUM ALLOYS
NIOBIUM BASE ALLOYS
PHYSICAL PROPERTIES
STRAINS
SUPERCONDUCTIVITY
TIN ALLOYS