Results 201 to 210 of about 128,309 (243)

Vaporization Behavior of Niobium Carbide

The Journal of Chemical Physics, 1962
The vaporization behavior of niobium carbide was studied over the temperature range from 2260° to 2940°K utilizing the Langmuir method. NbC was observed to lose carbon preferentially down to a composition of NbC0.75, at which composition the vaporization proceeds congruently at a temperature of 2940°K.
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Synchrotron radiation studies of the formation of niobium carbide layers on niobium

Physical Review B, 1984
The formation of a NbC overlayer on Nb has been observed with the use of valence-band photoemission, near-edge absorption at the C K edge, and photon- and electron-stimulated Auger decay. The sample was produced by depositing an amorphous C layer on a Nb substrate either by dc glow discharge in a hydrocarbon ambient or by sputtering from a graphite ...
D. Wesner, S. Krummacher, Myron Strongin, R. Carr, T. K. Sham, W. Eberhardt, S. L. Weng   +6 more
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Solubility of niobium carbide and niobium carbonitride in alloyed austenite and ferrite

Metallurgical Transactions A, 1984
The available data on the solubility of niobium carbide and niobium carbonitride in plain carbon and alloyed austenite has been analyzedvia dilute solution thermodynamics with a view to establishing a consistent set of interaction parameters for predicting austenite + niobium carbonitride equilibria. The computation algorithm includes the prediction of
R. C. Sharma, V. K. Lakshmanan, J. S. Kirkaldy   +2 more
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Gas evolution from zirconium carbide, niobium carbide, and tantalum carbide powders

Soviet Powder Metallurgy and Metal Ceramics, 1986
This work was undertaken with the aim of determining the gas contents of zirconium carbide, niobium carbide, and tantalum carbide powders as functions of their processing history. A high-vacuum, high-temperature apparatus was used, connected to an oilless evacuation system and instruments for the mass-spectrometric measurement of amounts and ...
A. V. Makeev, V. V. Khromonozhkin, A. S. Maskaev, V. G. Vil'chinskii   +3 more
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Properties of zirconium carbide -niobium carbide alloys in their homogeneity region

Soviet Powder Metallurgy and Metal Ceramics, 1971
1. A study was made of the electrical resistivity, thermo-emf, Hall coefficient, magnetic susceptibility, and temperature dependence of electrical resistivity and thermo-emf (at 50–1000°C) of binary solid solutions of zirconium and niobium carbides in their homogeneity region (C/Me =0.9–1.0). 2.
G. V. Samsonov, G. Sh. Upadkhaya
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Synthesis of niobium carbides in copper melts

Russian Metallurgy (Metally), 2010
The production of cast composite Cu-NbC alloys by synthesizing of niobium carbides in a copper melt is studied. The processes of carbide formation are intensified by the mechanical activation of niobium and graphite powders, which are mixed with a copper melt, in a high-speed ball mill and by the action of low-frequency vibrations on copper melts.
L. E. Bodrova, E. A. Popova, E. A. Pastukhov, A. V. Dolmatov, E. Yu. Goida   +4 more
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Sintering of alumina-niobium carbide composite

International Journal of Refractory Metals and Hard Materials, 1998
Abstract Several studies have been focused on particulate-dispersed Al 2 O 3 composites in order to improve both room and high temperature mechanical properties and wear resistance. In the present work Al 2 O 3 -NbC composites have been pressureless sintered and their microstructures analysed as a function of NbC and Y 2 O 3 concentration, the ...
Rosa M.R. Pasotti, Ana Helena A. Bressiani, Jose´C. Bressiani   +2 more
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Some features of the sintering of niobium carbide

Soviet Powder Metallurgy and Metal Ceramics, 1965
A study was made of the sintering of niobium carbide in electric furnaces. It is shown that niobium carbide parts can be sintered at relatively low temperatures (2400–2500°C) if activating additions are used. An addition of ammonium chloride activates sintering by creating a defective structure, which results in a considerable intensification of the ...
A. D. Panasyuk, P. S. Kislyi
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A kinetic study on oxidation of niobium carbide

Solid State Ionics, 1993
Abstract The isothermal oxidation of NbC powders was carried out at temperatures of 420–600°C and oxygen pressures of 4, 8 and 16 kPa, using an electro-microbalance. The oxidation process was divided into three steps I to III. In step I, oxidation occurs linearly in initial period (a degree of oxidation (α)
Shiro Shimada, Michio Inagaki
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Lattice dynamics of niobium carbide (NbC)

Solid State Communications, 1984
Abstract A consistent and comprehensive approach has been adopted to derive the framework of a deformation dipole model (DDM) which is capable of explaining successfully the lattice dynamics of ionic crystals. The application of this model to the case of the niobium carbide crystal has reproduced fairly well the phonon dispersion curves.
R.B. Yadav, K.C. Thakur
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