Hafniumcarbid

Bezeichnung:Hafniumcarbid

CAS-Nr12069-85-1

Englisch Name:HAFNIUM CARBIDE

CBNumberCB0124513

SummenformelCHf

Molgewicht190.5

MOL-Datei12069-85-1.mol

Synonyma

Hafniumcarbid

Hafniumcarbid physikalisch-chemischer Eigenschaften

Schmelzpunkt	2930 °C(lit.)
Dichte	12.2 g/mL at 25 °C(lit.)
RTECS-Nr.	MG4620000
Aggregatzustand	Powder
Farbe	Gray
Widerstand (resistivity)	45.0 (ρ/μΩ.cm)
Wasserlöslichkeit	it is insoluble in water.
Crystal Structure	Cubic, NaCl Structure
Expositionsgrenzwerte	ACGIH: TWA 0.5 mg/m3 NIOSH: IDLH 50 mg/m3; TWA 0.5 mg/m3
InChIKey	NVDNLVYQHRUYJA-UHFFFAOYSA-N
CAS Datenbank	12069-85-1
EPA chemische Informationen	Hafnium carbide (HfC) (12069-85-1)

Sicherheit

RIDADR	UN3178
WGK Germany	3
TSCA	Yes
HazardClass	4.1
PackingGroup	III

Gefahreninformationscode (GHS)

HAFNIUM CARBIDE Chemische Eigenschaften,Einsatz,Produktion Methoden

Chemische Eigenschaften
dark, gray, brittle solid; fcc, a=0.4640 nm; high cross section for absorption of thermal neutrons; resistivity 8.8μohm· cm; most refractory binary material known; hardness 2300kgf/mm2; used in control rods of nuclear reactors; can be prepared by heating HfO2 with lampblack under H2 at 1900°C–2300°C; used in crucible form for melting hafnium oxide, other oxides [KIR80] [HAW93] [CER91]
Physikalische Eigenschaften
Dark gray brittle solid, most refractory binary material known. Controls rods in nuclear reactors, crucible container for melting HfO and other oxides. 2 Corrosion resistant to liquid metals such as Nb, Ta, Mo, and W. Severe oxidation in air above 1100–1400°C and stable up to 2000°C in helium.
Verwenden
Hafnium carbide (HfC) with a melting point over 3890°C is a refractory binary compound. HfC and NbC can also be used as refractory coatings in nuclear reactors. The mixed carbide Ta4HfC5 possesses the highest melting point of any currently known compound at 4215°C.
Verwenden
It is an ideal metal in the manufacture of control rods for nuclear reactors.
Verwenden
Used for preparation of ultra-high temperature ceramics 1 Reactant in synthesis of hafnium-containing organometallic polymers 2 Additive in alloys 3 Used in coatings 4
Vorbereitung Methode
Hafnium carbide is a dark gray, brittle solid. It can be prepared by heating a mixture of the elements or by reacting hafnium tetrachloride with methane at 2100 C. Sufficient quantities of hafnium oxide or hafnium metal sponge are obtained during the large-scale production of pure zirconium for nuclear reactors. On an industrial scale, hafnium carbide can be produced from the hydrided hafnium sponge at 1500–1700 ℃ or from hafnium oxide at 2000–2200 ℃ by carburization in vacuo in the presence of hydrogen. The resulting carbide contains almost the theoretical quantity of carbon (6.30% °C) and a maximum of 0.1% free carbon (219). The hafnium carbide obtained is not a true stoichiometric compound as much as a solution of carbon at specific interstitial sites of a face-centered cubic hafnium lattice.
Hafnium carbide is inert to most reagents at room temperature but is dissolved by hydrofluoric acid solutions. Hafnium carbide reacts exothermally with halogens at 250–500 ℃to form hafnium tetrahalide, and to form hafnium oxide with oxygen above 500℃. In the presence of hydrogen, hafnium carbide slowly loses some of its carbon at higher temperatures.

Hafniumcarbid Anbieter Lieferant Produzent Hersteller Vertrieb Händler.

12069-85-1, HAFNIUM CARBIDE Verwandte Suche:

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