High temperature mechanical properties of polycrystalline hafnium …
Corpus ID: 137679412; High temperature mechanical properties of polycrystalline hafnium carbide and hafnium carbide containing 13-volume-percent hafnium diboride
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Insights into the Bond Behavior and Mechanical …
Abstract. Hafnium carbide (HfC) is a potential candidate of ultrahigh-temperature ceramics (UHTCs) and has attracted significantly widespread interest in recent years. Here, we have synthesized high-purity HfC samples with NaCl-type structure by using a high-pressure …
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Staff View: Hafnium : :: Library Catalog Search
High-temperature mechanical properties of polycrystalline hafnium carbide and hafnium carbide containing 13-volume-percent hafnium diboride / by: Sanders, William A., et al. Published: (1969) Tantalum : geochemistry, production, and potential applications / Published: (2015) On being well-coordinated : a half-century of research on transition ...
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Ablation resistance and thermal conductivity of …
Ablation resistance and thermal conductivity of carbon/carbon composites containing hafnium carbide - ScienceDirect. Corrosion Science. Volume 75, October …
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On the chemistry of the carbides in a molybdenum base Mo …
For improved visualization the phase interfaces are marked with white lines. Additionally, it can be observed that the carbide is approximately 500 nm in thickness. The same preparation procedure and the corresponding preparation progress are shown in Fig. 5 c and d for a tip containing hafnium carbide. In contrast to the specimen with the ...
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Hafnium-Containing Nanocomposites
For example, the melting point of hafnium carbide is as high as 3928 ± 20 °C [2] and is only exceeded by that of tantalum carbide (3,983 °C). Hafnium compounds are widely …
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Hafnium Carbide-based ceramics: processing and properties
Hafnium carbide is an excellent candidate material as a high temperature solar absorber and conductors because of its high melting point temperature of 3316°C, and because it is one of the few bulk materials that possess an intrinsic spectral selectivity [1, 2]. ... The mechanical properties of the composites containing 1-9 vol% MoSi2 were ...
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Hafnium
While hafnium nitride is the most refractory of all the metal nitrides, hafnium carbide is the most refractory of all the binary materials. With a melting point of about 3900 °C it is one of the most refractory binary compounds known. Hafnium has been successfully alloyed with several metals including iron, titanium and niobium.
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Elasticity, mechanical and thermal properties of …
Hafnium carbide (HfC) and tantalum carbide (TaC), as potential ultra-high temperature ceramics (UHTCs), have attracted widespread attention due to their unique physical and chemical properties. Here, dense HfC and TaC ceramics are synthesized under high pressure and high temperature 15 GPa and 1700 °C, respectively. The sound …
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Preceramic polymers to hafnium carbide and hafnium …
a. melting a hafnium containing preceramic polymer; b. extruding said polymer through an orifice to form fiber; c. cross-linking said fiber; and d. heating said cross-linked fiber under controlled atmospheric conditions at a temperature greater than 600 degrees centigrade to obtain a hafnium carbide containing ceramic fiber.
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The Hardworking Element Hafnium | ChemTalk
Hafnium carbide (HfC) is the most refractory binary compound, and hafnium nitride is the most refractory of all known metal nitrides. The compound hafnium disulfide (HfS 2) can …
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Electromagnetic interference shielding effectiveness of a …
Hafnium carbide nanowires (HfC nw) and a small amount of hafnium carbide nanobelts (HfC nb) were incorporated in a flexible carbon fiber felt by catalysis-assisted chemical vapor deposition to fabricate an electromagnetic interference (EMI) shielding carbon-based material with excellent electromagnetic wave absorption …
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Ultra-high temperature oxidation of a hafnium carbide …
Hafnium carbide-based solid solution ceramics with yttria additions were consolidated via hot pressing utilizing chromium carbide as a transient liquid sintering agent. Selected samples were oxidized at temperatures exceeding 2200 °C under high velocity airflow to determine their potential for service in ultra-high temperature …
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Microstructure and evolution of hafnium carbide whiskers …
Herein, hafnium carbide (HfC) whiskers are successfully fabricated in carbon fiber preforms via the polymer-derived ceramic (PDC) method. A novel carbon nanotube (CNT) template growth mechanism combined with the PDC method is proposed in this work, which is different from the conventional vapor–liquid–solid (VLS) mechanism …
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Fabrication and high-temperature performance evaluation of …
X-ray analysis results proposed that the SiC fiber containing hafnium carbide has a larger Burgers vector than a single silicon carbide fiber. The lattice diffusivity can be obtained experimentally, and based on bond energies (SiC:6.34, HfC:16.45 eV) [ 46, 47 ], the lattice constant, and melting points, hafnium carbide was found to have a ...
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Sol–Gel Synthesis of Highly Dispersed Tantalum Hafnium Carbide …
Complex tantalum hafnium carbide Ta 4 HfC 5 was synthesized according to a hybrid procedure. At the first stage of it, by the hydrolysis of tantalum- and hafnium-containing precursors in the presence of a polymer source of carbon (LBS-1 phenolformaldehyde resin), gel formation, drying, and carbonization under dynamic …
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Insights into the Bond Behavior and Mechanical Properties of Hafnium
Hafnium carbide (HfC) is a potential candidate of ultrahigh-temperature ceramics (UHTCs) and has attracted significantly widespread interest in recent years. Here, we have synthesized high-purity HfC samples with NaCl-type structure by using a high-pressure solid-solid reaction. The structural stability, equation of state, plastic …
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The structure and composition of hafnium …
of hafnium carbide, specimens of varying compositions were synthesized from 99.5% pure metallic hafnium, containing 0.3% Zr, and spectroscopically pure graphite, and also by …
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Pressureless Sintering of Hafnium Carbide–Silicon Carbide …
Pressureless Sintering of Hafnium Carbide–Silicon Carbide Ceramics. HfC-30 vol%SiC ceramics with a relative density of 99.7% was obtained by pressureless sintering at 2300°C for 0.5 h. The resultant ceramics showed fine microstructure with HfC grain size around 1 μm. The hardness (20.5 ± 0.2 GPa), bending strength (396 ± 56 …
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High-temperature mechanical properties of polycrystalline hafnium …
High-temperature mechanical properties of polycrystalline hafnium carbide and hafnium carbide containing 13-volume-percent hafnium diboride. by William A. Sanders and Hubert B. Probst. Resource Type: E-Book. Publication: Washington, D.C. : National Aeronautics and Space Administration, January 1969. Related Series: ...
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Optical characterization of hafnium boride and hafnium carbide …
Along the same line, in this work we measured and compared the optical properties of highly dense hafnium-based monophasic and composite UHTCs, namely hafnium boride (HfB 2), hafnium carbide (HfC), and some of their silicon carbide (SiC) containing composites, i.e. the binary HfB 2-SiC and the ternary HfB 2-HfC-SiC, …
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Mechanical properties of molybdenum containing MoO2 …
In this study, nominally pure molybdenum and three compositions containing Mo 1-x ... The hafnium carbide powder (12.2 g/cm 3) (Reade Advanced Materials, Newton, MA) had a purity of 99% with average particle diameters between 1 μm and 3 μm. Table 1. Compositions of Mo 1-x (HfC) x samples.
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Scientists develop the most heat-resistant material ever created
The triple hafnium-carbon-nitrogen system, hafnium carbonitride (Hf-C-N), was chosen, as scientists from Brown University (U.S.) ... hafnium carbide. To do this, we placed compressed HFC and HfCN ...
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Hafnium Carbide ( HfC )
Download PDF Copy. Request Quote. Jan 8 2004. The chemical formula for Hafnium Carbide is HfC. It is the most refractory binary compound known to man. …
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The structure and composition of hafnium carbide
C, O, N, containing 5% Zr. Hafnium carbide is the most refractory binary compound known (m.p. 3900~ and its properties are of con- siderable interest in modern techniques. Literature data on the composition and structure of hafnium carbide are very limited. In [1, 2], it was indicated
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Fabrication and high-temperature performance evaluation of …
For high-temperature property evaluation, bend stress relaxation tests were conducted at temperatures in the range of 1000–1500 °C, and the effects of hafnium carbide were compared with those ...
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(PDF) Microstructure and evolution of hafnium carbide …
Carbon nanotubes (CNTs) are fabricated in carbon cloth by ultilizing the waste gases when fabricating hafnium carbide nanowires (HfCNWs) through thermal pyrolysis of Hf-containing polymer precursor.
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Analyzing Tantalum Carbide (TaC) and Hafnium Carbide …
The TPS is an isolator material which have range temperature −121 °C until 1.649 °C. This paper analyzes Tantalum Carbide (TaC) and Hafnium Carbide (HfC) for spacecraft material. We show that Tantalum Carbide (TaC) and Hafnium Carbide (HfC) would rise above the TPS materials temperature. The comparison among RCC, HRSI, …
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Bond characteristics, mechanical properties, …
Bond characteristics, mechanical properties, and high-temperature thermal conductivity of ultrahigh-temperature ceramics (UHTCs), hafnium carbide (HfC), tantalum carbide (TaC), and their …
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Behavior of Some Refractory Hafnium and Tantalum Compounds …
Abstract—. By reacting tantalum or hafnium carbide with iridium in the presence of a small amount of silicon, we have prepared refractory hafnium- and tantalum-containing materials consisting of a mixture of phases: the intermetallic compound MIr 3, recrystallized tantalum or hafnium carbide, and iridium silicide.We have studied the …
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