Back to Search
Start Over
Self-organized, size-selection of precipitates during severe plastic deformation of dilute Cu-Nb alloys at low temperatures
- Source :
- Acta Materialia. 140:217-223
- Publication Year :
- 2017
- Publisher :
- Elsevier BV, 2017.
-
Abstract
- High pressure torsion (HPT) experiments have been carried out at very low temperatures (−78 °C) on dilute Cu-Nb alloys. The samples were prepared by magnetron sputtering to create solid solutions containing nominally between 1 at.% and 10 at.% Nb. Some samples were pre-annealed to 700 °C to form large Nb precipitates, ∼75 nm in radius, prior to HPT. For the unannealed alloys, HPT at low temperatures led to alloy decomposition for alloys with concentrations greater than ∼2 at.% Nb, with the steady state concentration of Nb increasing from ∼1.5 to ∼3 at.% as the initial concentration of Nb was increased. It was also observed that BCC Nb precipitates formed during low-temperature HPT, with a steady state precipitate size ∼10 nm in radius, which was insensitive to alloy concentration. HPT of pre-annealed Cu-10 at.% alloy led to the same steady state microstructure as the unannealed sample, indicating that the steady state during the low temperature HPT process is independent of the initial state for these Cu-Nb alloys. A model for phase evolution in strongly immiscible alloys during severe, low-temperature deformation is offered and implemented through kinetic Monte Carlo simulations. Good agreement with experiment is obtained.
- Subjects :
- 010302 applied physics
Materials science
Polymers and Plastics
Precipitation (chemistry)
Metallurgy
Alloy
Metals and Alloys
Analytical chemistry
02 engineering and technology
Atmospheric temperature range
engineering.material
021001 nanoscience & nanotechnology
Microstructure
01 natural sciences
Concentration ratio
Electronic, Optical and Magnetic Materials
0103 physical sciences
Ceramics and Composites
engineering
Steady state (chemistry)
Severe plastic deformation
0210 nano-technology
Solid solution
Subjects
Details
- ISSN :
- 13596454
- Volume :
- 140
- Database :
- OpenAIRE
- Journal :
- Acta Materialia
- Accession number :
- edsair.doi...........01eacc40d69712400bf7390c1a5b77d9