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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First-principles investigation of structural, mechanical, electronic, and thermoelectric properties of Half-Heusler compounds RuVX (X=As, P, and Sb)
TL;DR: In this paper, the structural, mechanical, electronic, and transport properties of RuVX (As, P, and Sb) Half-Heusler compounds are studied using the density functional theory (DFT) based on full-potential linearized augmented plane wave FP-LAPW method as integrated in the Wien2k code.
Journal ArticleDOI
First-principles calculations on elasticity and the thermodynamic properties of TaC under pressure
TL;DR: In this article, first principles on the elastic and the thermodynamic properties of TaC have been carried out with the plane-wave pseudopotential density functional method, and the calculated values are in very good agreement with experimental data as well as with some of the existing model calculations.
Journal ArticleDOI
Accelerating exploitation of Co-Al-based superalloys from theoretical study
Weiwei Xu,Shun Li Shang,Cheng Wang,Tieqiang Gang,Y.F. Huang,Li-Chuan Chen,X.J. Liu,Zi Kui Liu +7 more
TL;DR: In this article, the effect of alloying elements on phase stabilities and mechanical properties of Co3Al was investigated and it was shown that elastic properties are roughly in inverse proportional to the volume change induced by Alloying elements within each group of 3d, 4d or 5d.
Journal ArticleDOI
First-principles study of the structural and elastic properties of Cr2AlX (X=N, C) compounds
TL;DR: The structural, electronic and elastic properties of Cr 2 Al X, with X =N, C, have been investigated at the density functional theory level by applying a plane-wave pseudopotential approach.
Journal ArticleDOI
On the effects of surface coatings on the high-temperature oxidation of nickel
TL;DR: In this paper, Ni and Ni coated with superficial oxide coatings including SiO2, CeO2 and La2O3 have been oxidized in the temperature range 500-1200 °C in 10−4-1 atm oxygen.
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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