Characterization of the strength and microstructural evolution of a heavily cold rolled Cu-20% Nb composite
- Ames Lab., USDOE, Iowa State Univ., Ames, IA (US)
The mechanical properties and microstructures have been evaluated for a heavily cold rolled Cu-20 vol.% Nb composite. The strength of the rolled composite dramatically increases with increasing rolling deformation up to a true strain of 6.9, the maximum investigated. Longitudinal and transverse specimens both possessed equivalent mechanical properties. The unusually high tensile strengths observed in this material are dependent upon the microstructures which develop during cold rolling. Nb elongates during deformation, and forms ribbon-like filaments that are perfectly aligned parallel to the sheet surface, that is, in two directions longitudinal and transverse, while the Cu matrix undergoes a cycle of deformation-dynamic recovery-recrystallization which allows for the further reduction of the Nb. The dislocation density of the Cu matrix is found to be on the order of 10{sup 10}/cm{sup 2} throughout the rolling process. The strengthening in rolled and wire drawn Cu-Nb correlates with the amount of deformation in a similar manner even though during wire drawing the Nb filaments curl bout the wire axis and, therefore, are aligned only in the longitudinal direction. As a consequence of the Nb morphological difference in the sheet versus the wire composite, strengthening in the sheet does not show a Hall--Petch relationship, as the wire does, but a much weaker dependence on Nb filament spacing. Strengthening in the rolled composite is in accord with a modified rule of mixtures model but this model cannot account for the observed strengthening in wire drawn Cu-Nb.
- DOE Contract Number:
- W-7405-ENG-82
- OSTI ID:
- 6815788
- Journal Information:
- Acta Metallurgica; (USA), Journal Name: Acta Metallurgica; (USA) Vol. 37:7; ISSN 0001-6160; ISSN AMETA
- Country of Publication:
- United States
- Language:
- English
Similar Records
Microstructure-strength relationships of heavily deformed Cu-based composites
Characterization of the strength and microstructure of heavily cold worked Cu-Nb composites
Related Subjects
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
360203 -- Ceramics
Cermets
& Refractories-- Mechanical Properties
360204 -- Ceramics
Cermets
& Refractories-- Physical Properties
656100 -- Condensed Matter Physics-- Superconductivity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
COMPOSITE MATERIALS
COPPER COMPOUNDS
CRYSTAL STRUCTURE
DENSITY
FABRICATION
HALL EFFECT
MATERIALS
MATERIALS WORKING
MECHANICAL PROPERTIES
MICROSTRUCTURE
NIOBIUM COMPOUNDS
PHYSICAL PROPERTIES
RECRYSTALLIZATION
REFRACTORY METAL COMPOUNDS
ROLLING
SUPERCONDUCTING WIRES
TRANSITION ELEMENT COMPOUNDS
WIRES