Journal ArticleDOI
A quantitative demonstration of the grain boundary diffusion mechanism for the oxidation of metals
TLDR
In this article, the authors report measurements of the oxide scale thickness and oxide grain size as a function of time during the oxidation of high-purity nickel in the temperature range 500-800°C.Abstract:
Below 1000°C the oxidation of nickel cannot be controlled by the diffusion of ions through the bulk crystal lattice of the pure oxide, because the measured oxidation rates are several orders of magnitude faster than would be predicted on this basis. Short-circuit diffusion through oxide grain boundaries or dislocations has usually been held responsible, but there has hitherto been no proper quantitative confirmation of this mechanism. We report measurements of the oxide scale thickness and oxide grain size as a function of time during the oxidation of high-purity nickel in the temperature range 500–800°C. All the oxidation experiments were carried out in pure oxygen at a pressure of one atmosphere. The measured parabolic oxidation rate constants have been compared with those calculated from grain boundary diffusion data obtained in our previous work, using a grain boundary diffusion model for the oxidation process. The quantitative agreement between measured and calculated oxidation rates shows c...read more
Citations
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A DFT study of mechanical properties, thermal conductivity and electronic structures of Th-doped Gd2Zr2O7
TL;DR: In this article, a systematic density functional theory study is performed to investigate the mechanical stability, elastic moduli, Debye temperature, thermal conductivity and electronic structures of Gd 2- y Th y Zr 2 O 7 and Gd2 Zr2-y Th y O 7 compositions.
Journal ArticleDOI
High-pressure structural, elastic, and thermodynamic properties of zircon-type HoPO4 and TmPO4
Oscar Gomis,Barbara Lavina,Plácida Rodríguez-Hernández,Alfonso Muñoz,R. Errandonea,D. Errandonea,Marco Bettinelli +6 more
TL;DR: The calculations indicate that the possible causes that make the zircon structure unstable are mechanical instabilities and the softening of a silent B 1u mode.
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Ab initio-predicted micro-mechanical performance of refractory high-entropy alloys
TL;DR: These investigations suggest that intrinsically ductile HEAs with high ideal strength can be achieved by controlling the proportion of group four elements to group five elements.
Journal ArticleDOI
Five carbon allotropes from Squaroglitter structures
TL;DR: In this paper, the authors addressed the computational prediction of five new allotropes based on the Squaroglitter structure (tP8 carbon) and found that they display dynamical and mechanical stability.
Journal ArticleDOI
First principles calculation of intermetallic compounds in FeTiCoNiVCrMnCuAl system high entropy alloy
TL;DR: In this paper, the structural, electronic and elastic properties of common intermetallic compounds in FeTiCoNiVCrMnCuAl system high entropy alloy were investigated by the first principles calculation.
References
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Journal ArticleDOI
Beitrag zur Theorie des Anlaufvorgangs
TL;DR: The Mechanismus des Diffusionsvorgangs is still weitgehend unbekannt as discussed by the authors, i.e., the Diffusion of mindestens einem der beiden Bestandteile durch die Anlaufschicht is notwendig.
Journal ArticleDOI
The diffusion of 63Ni along grain boundaries in nickel oxide
A. Atkinson,R. I. Taylor +1 more
TL;DR: The product of the grain boundary diffusion coefficient and width, D′δ, has been measured directly for the diffusion of 63Ni along grain boundaries in high-purity NiO as discussed by the authors.
Journal ArticleDOI
The role of oxide microstructure and growth stresses in the high-temperature scaling of nickel
F. N. Rhines,J. S. Wolf +1 more
TL;DR: In this article, the formation of new nickel oxide upon boundaries of columnar grains where nickel diffusing through the oxide crystals, meets oxygen, diffusing along grain boundaries is identified as the primary cause of this stress.
Journal ArticleDOI
The diffusion of Ni in the bulk and along dislocations in NiO single crystals
A. Atkinson,R. I. Taylor +1 more
TL;DR: In this paper, diffusion profiles of 63Ni tracer in single crystals of NiO following anneals at 522°-1000°C have been determined by a radio-frequency sputter-sectioning technique.
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