Oxygen Diffusion Modeling in Titanium Alloys: New Elements on the Analysis of Microhardness Profiles
| Autor: | Nicolas Vaché, Daniel Monceau |
|---|---|
| Přispěvatelé: | Centre interuniversitaire de recherche et d'ingenierie des matériaux (CIRIMAT), Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC), Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE) |
| Rok vydání: | 2020 |
| Předmět: |
Microprobe
Materials science Oxygen diffusion coefficient Matériaux 020209 energy chemistry.chemical_element Thermodynamics 02 engineering and technology Thermal diffusivity 01 natural sciences Oxygen [SPI.MAT]Engineering Sciences [physics]/Materials Inorganic Chemistry symbols.namesake Oxidation 0103 physical sciences 0202 electrical engineering electronic engineering information engineering Materials Chemistry Physics::Chemical Physics Diffusion (business) Titanium 010302 applied physics Arrhenius equation Microhardness profile Modeling Metals and Alloys Titanium alloy Atmospheric temperature range chemistry symbols Limiting oxygen concentration |
| Zdroj: | Oxidation of Metals Oxidation of Metals, Springer Verlag, 2020, 93 (1-2), pp.215-227. ⟨10.1007/s11085-020-09956-9⟩ |
| ISSN: | 1573-4889 0030-770X |
| DOI: | 10.1007/s11085-020-09956-9 |
| Popis: | International audience; This study focuses on the diffusion of oxygen in titanium alloys during high-temperature oxidation. In particular, the model used to obtain thermokinetic coefficients from microhardness profiles was investigated. A literature review shows that microhardness profiles are modeled by a simple error function in the same way as oxygen concentration profiles obtained by microprobe analysis (EPMA). The analysis of literature shows that the hypothesis of a linear relationship between microhardness and oxygen content is not true over the entire oxygen concentration range and that a parabolic relationship is empirically more accurate. A new modeling equation taking into account this parabolic law is proposed as well as a simplified and easier to use form. The relative error of the diffusion coefficients obtained using the simplified equation was then determined. This new model was applied to the experimental microhardness profile of a Ti-6242s sample oxidized at 625 °C. The resulting oxygen diffusion coefficient is in excellent agreement with the one determined from EPMA profile using the classic error function model. Finally, other data from literature were analyzed with the new model to obtain an Arrhenius diagram of oxygen diffusivity in Ti-64 alloy between 550 and 850 °C. This diagram gives thermokinetic coefficients D0=1.1×10−5exp(−191kJ/molRT) that are close to those reported for pure α-Ti in the temperature range 550–850 °C |
| Databáze: | OpenAIRE |
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