Bond characteristics, mechanical properties, and high-temperature thermal conductivity of ultrahigh-temperature ceramics (UHTCs), hafnium carbide (HfC), tantalum carbide (TaC), and their …

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.

High-temperature mechanical properties of polycrystalline hafnium carbide and hafnium carbide containing 13-volume-percent hafnium diboride: Author: Sanders, William A. Author: Probst, Hubert B. Author: United States. National Aeronautics and Space Administration: Author: Lewis Research Center:

Hafnium-containing nanocomposites are prepared using polymermediated synthesis and controlled thermolysis. The new types of Hf-containing monomers and polymers were synthesized. ... Some Parameters of the Preparation of Hafnium Carbide Coatings from Hafnium Acetylacetonate, High Pure Compounds, (5): 45–47. Google Scholar. …

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 …

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 …

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 …

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.

@article{osti_5896908, title = {Process for producing high hafnium carbide containing alloys}, author = {Grant, N J and Robinson, R K}, abstractNote = {Disclosed is a process for forming a new group of cobalt-based alloys containing 3-18% hafnium carbide (HfC), the HfC having a particle size finer than about three microns. The class of alloys exhibits …

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 …

10 Citations. Explore all metrics. Abstract. Hafnium carbide HfC (at%: 42%C; 49%Hf; 7%O) was investigated under rapid heating by a current pulse, in a time …

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 …

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 …

Hafnium diboride (HfB2)- and hafnium carbide (HfC)-based materials containing MoSi2 as sintering aid in the volumetric range 1%–9% were densified by spark plasma sintering at temperatures ...

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

hafnium containing preceramic polymer, extruding that polymer through an orifice to form fiber, cross-linking that fiber and heating the cross-linked fiber under controlled atmospheric conditions at a temperature greater than 600°C to obtain a hafnium carbide containing ceramic fibre. [6] Possible applications of HfC composites are:

Corpus ID: 137679412; High temperature mechanical properties of polycrystalline hafnium carbide and hafnium carbide containing 13-volume-percent hafnium diboride

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 ...

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, …

Among compounds of three elements, the mixed carbide of tungsten and hafnium has the single highest melting point of any known compound at 7,457 degrees F (4,125 degrees C), according to Chemistry ...

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 ...

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.

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 ...

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 …

Hafnium-containing silicates have been observed to limit the oxygen diffusion more than pure silica [15]. Several methods have been developed to introduce UHTCs phases into or coatings onto C/C composites in order to improve the C/C oxidation resistance. Chemical vapour deposition (CVD) of HfC coating was reported by Wang et …

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 …

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: ...

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.

Herein, hafnium carbide (HfC) whiskers are successfully fabricated in carbon fiber preforms via the polymer-derived ceramic (PDC) method. ... CH4 during the pyrolysis of a Hf-containing precursor ...

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 …

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, …

Hafnium carbide (HfC) is a refractory compound known for its exceptional mechanical, thermal, and electrical properties. This compound has gained significant …

Hafnium carbide (HfC) is a refractory compound known for its exceptional mechanical, thermal, and electrical properties. This compound has gained significant attention in materials science and engineering due to its high melting point, extreme hardness, and excellent thermal stability. This study presents crystal structure prediction …

coatings. 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 used in the fabrication of composites capable of withstanding high temperatures and aggressive attack and also in basic organic

Abstract. We demonstrate fabrication of a two-dimensional Hf-containing MXene, Hf 3 C 2Tz, by selective etching of a layered parent Hf 3 [Al (Si)] 4 C 6 compound. A substitutional solution of Si on Al sites effectively …

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 …

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 ...

High temperature mechanical properties of polycrystalline hafnium carbide containing 13- volume-percent hafnium diboride. NTRS NTRS - NASA Technical Reports Server. Search. more_vert. Collections About News Help Login. As of October 27, 2023, NASA STI Services will no longer have an embargo for accepted manuscripts.

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. …