Results 141 to 150 of about 112,198 (176)

Dynamic Compaction of Combustion-Synthesized Hafnium Carbide

Journal of the American Ceramic Society, 1990
The explosive‐consolidation technique developed to fabricate combustion‐synthesized titanium carbide and titanium diboride has been applied to hafnium carbide. Presently, the application of this technique results in a moderately dense HfC product. Sample confinement and configuration, explosive loading, and total heat available for the combustion ...
Laszlo J Kecskes
exaly   +2 more sources

Fabrication of molybdenum carbide and hafnium carbide field emitter arrays

Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena, 2001
We report on a process for the fabrication of Mo2C and HfC refractory metal carbide field emitter arrays using a modified Spindt tip fabrication process. Measurements of the aspect ratios of emitter cones showed that Mo2C tip structures have an aspect ratio similar to Mo field emitter tips.
Yi Wei, Babu R. Chalamala, Gene Rossi, Kathleen Palmer, Bruce G. Smith, Robert H. Reuss   +5 more
openaire   +1 more source

High temperature diffusion of hafnium in tungsten and a tungsten-hafnium carbide alloy

Scripta Metallurgica et Materialia, 1994
Refractory metals and ceramics are used extensively in energy systems due to their high temperature properties. This is particularly important in direct conversion systems where thermal to electric conversion efficiency is a direct function of temperature.
Yo Ozaki, Ralph H. Zee
openaire   +1 more source

Analyzing Tantalum Carbide (TaC) and Hafnium Carbide (HfC) for Spacecraft Material

2021
Spacecraft needs thermal protection systems material that rise more than ±1.260 °C on nose cap and wing leading edge. It depends on the heat loading encountered during the re-entry of the orbiter into the atmosphere. Recently, the spacecraft uses thermal protection system (TPS) materials like reinforced carbon-carbon (RCC), High-Temperature Reusable ...
Sovian Aritonang, W. S. Ezha Kurniasari, Riyadi Juhana, Tutut Herawan   +3 more
openaire   +1 more source

Synthesis and Fabrication of High Purity Hafnium Nitride and Hafnium Carbide

Journal of Vacuum Science and Technology, 1972
The procedures used to prepare kilogram quanties of hafnium nitride and hafnium carbide powders and hot-pressed billets are described. In order to maintain high purity, all steps of the process were conducted in either a vacuum or a high purity atmosphere.
openaire   +1 more source

Chemical Vapor Deposition of an Iridium Phase on Hafnium Carbide and Tantalum Carbide

Russian Journal of Inorganic Chemistry, 2020
Nanocrystalline iridium coatings on hafnium carbide and tantalum carbide substrates are prepared by chemical vapor deposition (MOCVD) at 600°С. Subsequent high-temperature treatment at 1100°С gives rise to chemical reactions between iridium and hafnium carbide or tantalum carbide to yield nanosized substitutional intermetallic solid solutions MIr3 – x ...
V. V. Lozanov, I. Yu. Il’in, N. B. Morozova, S. V. Trubin, N. I. Baklanova   +4 more
openaire   +1 more source

Plastic flow and fracture of tantalum carbide and hafnium carbide at low temperatures

Journal of Materials Science, 1971
Knoop and Vickers hardness measurements have been made on tantalum carbide and hafnium carbide single crystals. The hardness varies with orientation of the indenter in the crystal, but indentations in the two carbides are of very different character, TaC behaves in a relatively ductile manner and deforms plastically before cracking, while HfC exhibits ...
D. J. Rowcliffe, G. E. Hollox
openaire   +1 more source

Thermodynamic modeling and preparation of hafnium carbide coatings in the hafnium–carbon–fluorine system

Inorganic Materials, 2016
Thermodynamic modeling of the Hf–C–F system has been carried out in wide temperature and pressure ranges. Analysis of the calculated molecular composition of the vapor phase in equilibrium with Hf + HfC and the vapor phase in equilibrium with C + HfC has shown that the chemical vapor transport of hafnium under isothermal conditions is mediated by lower
V. V. Lozanov, S. V. Sysoev, N. I. Baklanova   +2 more
openaire   +1 more source

Mechanically activated solid-state synthesis of hafnium carbide and hafnium nitride nanoparticles

Journal of Alloys and Compounds, 2008
Nanocrystalline hafnium nitrides and hafnium carbides are synthesized, from powder mixtures based on partially hydrated hafnium tetrachloride, ph-HfCl4, and on magnesium, by a three-step process, namely a short mechanical activation step followed by a brief annealing step and a leaching step.
Barraud, Elodie, Bégin-Colin, Sylvie, Le Caër, Gérard, Barres, Odile, Villiéras, Frédéric   +4 more
openaire   +2 more sources

High-Temperature Heat Content of Tungsten Carbide and Hafnium Carbide

The Journal of Chemical Physics, 1964
The heat content of tungsten carbide was measured between 1276° and 2642°K and that of hafnium carbide between 1286° and 2805°K using a drop calorimeter.
openaire   +1 more source