A study of phase decomposition in Cu-Ni-Fe alloys
- Univ. of Tohoku, Sendai (Japan). Dept. of Materials Science
- Univ. of Tokyo, Tokyo (Japan). Inst. for Solid State Physics
A study of phase decomposition in two Cu-Ni-Fe alloys was realized by AP-FIM. It was possible to confirm that phase decomposition takes place via spinodal decomposition in this alloy system, as the amplitude of the composition modulation increased with aging time without practically any change in the wavelength of the modulation. It was also observed that the morphology of the decomposed phases is related to the coherency-strain energy as predicted by Cahn's theory of spinodal decomposition. By analysis of the data of the modulation wavelength, it was possible to estimate the coherent spinodal temperature to be 800 [plus minus] 25 and 900 [plus minus] 25K in Cu-46 at.% Ni-4 at.% Fe and Cu-48 at.% Ni-8 at.% Fe alloys, respectively. In the early stage of decomposition, the change in modulation wavelength showed a time exponent as small as about 0.07. On the other hand, in the coarsening stage the change in the modulation wavelength agreed well with the LSW theory of thermally activated growth. The activation energy for this coarsening process was determined to be 216 [plus minus] 10 and 232 [plus minus] 10 kJ/mol in the Cu-46 at.% Ni-4 at.% Fe and Cu-48 at.% Ni-8 at.% Fe alloys, respectively. The compositions of the decomposed phases are consistent with the miscibility gap in the calculated equilibrium Cu-Ni-Fe phase diagram.
- OSTI ID:
- 6327765
- Journal Information:
- Acta Metallurgica et Materialia; (United States), Journal Name: Acta Metallurgica et Materialia; (United States) Vol. 41:1; ISSN 0956-7151; ISSN AMATEB
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360102* -- Metals & Alloys-- Structure & Phase Studies
ACTIVATION ENERGY
ALLOY SYSTEMS
ALLOYS
COPPER ALLOYS
CRYSTAL STRUCTURE
DATA
DATA ANALYSIS
DIAGRAMS
ENERGY
EXPERIMENTAL DATA
INFORMATION
ION MICROSCOPY
IRON ALLOYS
MICROSCOPY
MORPHOLOGY
NICKEL ALLOYS
NUMERICAL DATA
PHASE DIAGRAMS
PHASE STUDIES
SOLUBILITY
TEMPERATURE RANGE
TEMPERATURE RANGE 0400-1000 K
TERNARY ALLOY SYSTEMS