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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Journal ArticleDOI
The structural, electronic, elastic and thermodynamics properties of 2D transition-metal electride Y2C via first-principles calculations
TL;DR: In this article, the physical properties of layered structure heavy rare earths hypocarbide Y 2 C have been investigated via first-principles calculations within the framework of density functional theory.
Journal ArticleDOI
Shear anisotropy: Tuning high temperature metal hexaborides from soft to extremely hard
TL;DR: In this paper, a combination of the empirical hardness model for polycrystalline materials and density functional theory investigation was used to establish the hardness dependence on shear anisotropic factors of high temperature metal hexaborides.
Journal ArticleDOI
Ab. initio study of the structural, elastic, electronic and optical properties of Cu3N
TL;DR: In this paper, the electronic, optical, elastic, properties of copper nitride (Cu3N) in cubic anti-ReO3 phase have been studied using the fullpotential augmented plane waves (FP-LAPW) within density functional theory (DFT) framework.
Journal ArticleDOI
Mechanical properties and bonding feature of the YAg, CeAg, HoCu, LaAg, LaZn, and LaMg rare-earth intermetallic compounds: An ab initio study
TL;DR: In this article, the fullpotential linearized augmented plane wave (FLAPW) method has been employed within the generalized gradient approximation (GGA) to investigate structural and elastic properties of YAg, CeAg, HoCu, LaAg, LaZn, LaMg compounds.
Journal ArticleDOI
Predicted structural evolution and detailed insight into configuration correlation, mechanical properties of silicon–boron binary compounds
Bo Zhang,Lailei Wu,Zhihong Li +2 more
TL;DR: In this paper, the crystal structures, phase stability, mechanical and electronic structures of silicon-boron binaries have been investigated systematically using first-principles of pseudopotential calculations, and the predicted bulk modulus of Si-B binaries is between 120 and 180 GPa, while there is a dramatic drop for two kinds of α-SiB3 in the shear modulus from 130.3 GPa to 71.1 GPa.
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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