Phosphorus interdiffusivity inα-Fe binary and alloy systems
| Autor: | William R. Graham, Gregory Luckman, Richard A. Didio |
|---|---|
| Rok vydání: | 1981 |
| Předmět: |
Auger electron spectroscopy
Materials science Transition temperature Diffusion Alloy Metallurgy technology industry and agriculture Metals and Alloys Analytical chemistry chemistry.chemical_element Activation energy engineering.material Atmospheric temperature range Condensed Matter Physics Isothermal process Crystallography chemistry Mechanics of Materials engineering Carbon |
| Zdroj: | Metallurgical Transactions A. 12:253-259 |
| ISSN: | 2379-0180 0360-2133 |
| DOI: | 10.1007/bf02655198 |
| Popis: | The isothermal segregation kinetics of phosphorus to Fe and Fe-based alloy surfaces have been monitored from 783 to 923 K using Auger electron spectroscopy. The P segregation kinetics are consistent with a model which assumes bulk diffusion of P to be the rate controlling mechanism in the segregation process. The activation energy and preexponential for P diffusion in Fe calculated from the diffusion data are 314 ± 30 kJ · mol−1 and 8 × 105 cm2s in the temperature range studied. Similar results are found for the carbon free Fe-based alloys studied. Phosphorus segregation kinetics for a carbon containing alloy are more rapid, with evidence of a dependence on carbon concentration. The activation energy and pre-exponential calculated in this study for carbon-free alloys are considerably higher than published values measured at higher temperatures by conventional techniques. It is pointed out that an increase in activation energy with decreasing temperature is consistent with observations in several studies of Fe and other ferromagnetic alloys of an increase in activation energy for diffusion below the ferromagnetic transition temperature. |
| Databáze: | OpenAIRE |
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