The Effect of Cr Content on the Oxidation Behavior of Ti-Cr-N Films
| Autor: | Daniel J. Foley, James E. Krzanowski |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2014 |
| Předmět: |
nitrides
X-ray photoelectron spectroscopy Materials science oxidation Diffusion Analytical chemistry Oxide Surfaces and Interfaces Nitride Atmospheric temperature range Surfaces Coatings and Films X-ray diffraction chemistry.chemical_compound chemistry lcsh:TA1-2040 X-ray crystallography Oxidizing agent Materials Chemistry Chromium nitride lcsh:Engineering (General). Civil engineering (General) |
| Zdroj: | Coatings, Vol 4, Iss 2, Pp 308-319 (2014) |
| ISSN: | 2079-6412 |
| Popis: | Ti1−xCrxN thin-film samples were sputter-deposited with lateral composition gradients x = 0.1–0.9 across each sample. In order to determine the effect of Cr content on oxidation, samples were air-oxidized at temperatures ranging from 650 to 950 °C. The extent and type of oxide formed was characterized using X-ray diffraction. Only minor oxidation was observed for the 650–750 °C temperature range. At 850 °C, films below x = 0.7 showed poor oxidation resistance, with the formation of TiO2 and Cr2O3 oxides, but little oxidation occurred above x = 0.7. At 950 °C, films above x = 0.7 again exhibited the best oxidation resistance. Chromium nitride films, which deposited as Cr2N, were found to begin oxidizing at 750 °C, indicating that the increased oxidation resistance of the higher-Cr Ti-Cr-N films can be attributed to the Ti-induced stabilization of the B1-structured phase. A compositionally-uniform film (x = 0.79) was also deposited and analyzed by XPS before and after oxidation. Oxidation resulted in primarily Cr2O3 at the surface, with some TiO2 also present, with the oxide richer in Cr than the starting film composition. These results suggested that at higher Cr compositions in the film, the oxidation mechanism was controlled by Cr diffusion to the surface. |
| Databáze: | OpenAIRE |
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