Relaxation mechanisms in Fe-Al-C alloys
- 1 February 2003
- journal article
- Published by Springer Science and Business Media LLC in Metallurgical and Materials Transactions A
- Vol. 34 (2), 255-266
- https://doi.org/10.1007/s11661-003-0327-2
Abstract
The relaxation spectrum of Fe-Al alloys has been studied as a function of Al content and ordering reaction in Fe-Al. Three types of relaxation peaks are observed, with activation energies between 0.8 and 3 eV. Snoek-type relaxation is studied in Fe-(0 to 50 at. pct)Al and compared with the Snoek relaxation in pure iron (C in α-Fe), chromium (C in Cr), and nibium (O in Nb). The snoek-type relaxation peak in iron (at 314 K for 1 Hz) shifts to higher temperatures with increasing Al content in iron. Significant changes in the peak parameters occur when α-Fe is alloyed with Al, because of the ordering reaction in Fe-Al. Peculiarities of the carbon-atom distribution in ordered and disordered Fe-Al alloys are discussed using an atom-interaction model, in which the elastic interaction is supplemented by the chemical C-Al interaction. Two other peaks are observed only when a certain Al content is exceeded: a Zener peak for Fe-(>10 pct)Al and an X peak for Fe-(>26 pct)Al. Parameters of these peaks are discussed with respect to alloy structure. Three hypotheses are discussed for the X-peak mechanism with an activation energy about 1.7 eV. A map of relaxation peaks in the Fe-Al system is constructed.Keywords
This publication has 27 references indexed in Scilit:
- Vacancy Formation and Diffusion in FeAl-AlloysDefect and Diffusion Forum, 2001
- Thermal Point Defects in FeAl, CoGa and NiGa Intermetallic CompoundsDefect and Diffusion Forum, 2001
- Carbon-substitutional interaction in austeniteScripta Materialia, 2000
- Order-disorder changes in Fe3Al based alloys and the development of an iron-base α-α″ superalloyActa Materialia, 1996
- Solute interaction and internal friction spectra in solid solutionsActa Metallurgica et Materialia, 1992
- Internal Friction Studies on Oxygen–Oxygen Interaction in Niobium. II. Application of Long‐Range Interaction ModelsPhysica Status Solidi (b), 1992
- Computer simulation of strain-induced ordering in interstitial solutions based on the B.C.C. Ta latticephysica status solidi (a), 1980
- Frequency dependence of dielectric loss in condensed matterPhysical Review B, 1979
- The Effect of Atomic Order and Ferromagnetism on the Elastic and Anelastic Properties of Fe ‐ 25 atom % AlPhysica Status Solidi (b), 1963
- Effect of small quantities of carbon and nitrogen on the elastic and plastic properties of ironPhysica, 1941