Self-diffusion and fast cobalt impurity diffusion in the bulk and in grain boundaries of hexagonal titanium
| Autor: | Klaus Vieregge, Christian Herzig, Ralf Willecke |
|---|---|
| Rok vydání: | 1991 |
| Předmět: |
Self-diffusion
Materials science Physics and Astronomy (miscellaneous) Condensed matter physics Enthalpy Metals and Alloys Condensed Matter Physics Electronic Optical and Magnetic Materials Crystallography Vacancy defect Grain boundary diffusion coefficient Effective diffusion coefficient General Materials Science Orders of magnitude (data) Grain boundary Diffusion (business) |
| Zdroj: | Philosophical Magazine A. 63:949-958 |
| ISSN: | 1460-6992 0141-8610 |
| DOI: | 10.1080/01418619108213927 |
| Popis: | Bulk self-diffusion was measured in α-Ti single crystals between 776 and 1132 K using the radiotracer 44Ti and ion beam sputtering for profile sectioning. The results, which represent diffusion perpendicular to the c axis, follow a straight Arrhenius relation: Self-diffusion is interpreted by a vacancy mechanism. The low vacancy migration enthalpy may be related to the unusually low elastic constant c 66 in α-Ti. Grain-boundary self-diffusion was also measured in α-Ti; compared with corresponding results in other h.c.p. metals it was found to be in line with a vacancy mechanism. Grain-boundary diffusion of Co, which is a fast bulk diffuser, is six to seven orders of magnitude larger than grain-boundary self-diffusion. Even if a large Co grain-boundary segregation is accounted for, the evidence is that Co diffuses interstitially in α-Ti grain boundaries. |
| Databáze: | OpenAIRE |
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