hafnium carbide containing

Synthesis and Electrochemical Properties of Two …

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 …

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.

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 …

06/3201 Advanced Ceramic Fibers and Matrices: …

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:

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, …

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

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 …

Fabrication and high-temperature performance …

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 …

High-temperature mechanical properties of polycrystalline hafnium …

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:

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 …

Thermophysical properties for hafnium carbide (HfC) …

tent for a given carbide). Experimental techniques Figures 4a,b show a view of a glass cell containing HfC plate (a) and a clamped cell connected to the supply electrodes (b). A sample (1) of hafnium carbide (130 microns thick) in Fig. 4a was glued to the middle of the lower plate of glass with UV-cured glue and covered with the upper glass (2).

Process for producing high hafnium carbide containing …

@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-containing Nanocomposites

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. …

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 ...

Crystals | Free Full-Text | Hafnium Carbide: Prediction …

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

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 …

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 …

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.

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. …

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 …

Thermal properties of Cf/HfC and Cf/HfC-SiC composites …

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 …

Hafnium-Containing Nanocomposites

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

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 …

(PDF) Hafnium Carbide Coatings Deposited by Suspension …

Required parameters have been determined to ensure the synthesis of a powder containing ~ 98 wt. % of the cubic phase of hafnium carbide: heat treatment of the initial mixture containing the ...

Facts About Hafnium | Live Science

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 ...

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 ...

Hafnium | Definition, Atomic Mass, Properties, Uses, & Facts

Hafnium, chemical element, metal of Group 4 (IVb) of the periodic table. It is a ductile metal with a brilliant silvery luster. ... For some purposes separation of the two elements is not important; zirconium containing about 1 percent of hafnium is as acceptable as pure zirconium. ... The alloy tantalum hafnium carbide (Ta 4 HfC 5), with …

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 ...

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

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 …