| DOI | Resolve DOI: https://doi.org/10.1088/0022-3727/49/5/055306 |
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| Author | Search for: Chen, Kuiying1 |
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| Affiliation | - National Research Council of Canada. Aerospace
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| Format | Text, Article |
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| Subject | Activation energy; Calculations; Chemical bonds; Density functional theory; Oxidation resistance; Platinum; Sulfur; Thermal barrier coatings; Apparent activation energy; Associated electronics; Bonding characteristics; Diffusion mechanisms; Electron localization function; Nearest neighbour; Oxidation resistant; Preexponential factor; Diffusion |
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| Abstract | Diffusivities of detrimental impurity sulfur (S) in stoichiometric and Pt doped β-NiAl were evaluated using density functional theory calculations. The apparent activation energy and the pre-exponential factor of diffusivity via the next nearest neighbour (NNN) and interstitial jumps were evaluated to identify possible preferred diffusion mechanism(s). By calculating the electron localization function (ELF), the bonding characteristics of S with its surrounding atoms were assessed for the diffusion process. By comparison with the experimental results, the S diffusion through the NNN vacancy-mediated mechanism is found to be favoured. Addition of Pt in β-NiAl was found to significantly reduce the S diffusivity, and an associated electronic effect was explored. The elucidation of the above mechanisms may shed light on the development of new Pt-modified doped β-NiAl bond coats that can extend the life of oxidation resistant and thermal barrier coatings. |
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| Publication date | 2016-01-07 |
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| In | |
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| Language | English |
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| Peer reviewed | Yes |
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| NPARC number | 21277452 |
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| Export citation | Export as RIS |
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| Report a correction | Report a correction (opens in a new tab) |
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| Record identifier | a1730595-8ff4-4e84-9cc1-70639dc75d34 |
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| Record created | 2016-03-09 |
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| Record modified | 2020-03-16 |
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