Zirconium carbide

Crystal structure
	__ Zr 4+ __ C 4−
General
Surname	Zirconium carbide
other names	Zirconium (IV) carbide; Zirconium monocarbide;
Ratio formula	ZrC
Brief description	odorless gray solid
External identifiers / databases
EC number	235-125-1
ECHA InfoCard	100,031,920
PubChem	159434
Wikidata	Q2615051
properties
Molar mass	103.23 g mol −1
Physical state	firmly
density	6.73 g cm −3
Melting point	3540 ° C
boiling point	5100 ° C
solubility	almost insoluble in water
safety instructions
GHS labeling of hazardous substances Caution
H and P phrases	H: 228
	P: 210-241-280-240-370 + 378
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Zirconium carbide is an inorganic chemical compound from the group of carbides .

Extraction and presentation

Zirconium carbide can be prepared using the same processes as titanium carbide . It can do so through the carbothermal reduction of zirconium dioxide

{\ displaystyle \ mathrm {ZrO_ {2} +3 \ C \ longrightarrow ZrC + 2 \ CO}}

or by synthesis from the elements at more than 2000 ° C. Since zirconium carbide is very sensitive to nitrogen , very pure argon must be used for high sintering . During the reactions it should be noted that carbon dissolves in zirconium carbide, whereby its melting point drops to 3100 ° C. When it cools down, the carbon precipitates again.

{\ displaystyle \ mathrm {Zr + C \ longrightarrow ZrC}}

It can also be made from zirconium (IV) chloride .

{\ displaystyle \ mathrm {ZrCl_ {4} + \ CH_ {4} \ longrightarrow \ ZrC + 4 \ HCl}}

Production by plasma CVD is also possible.

properties

Zirconium carbide is an odorless gray powder that is practically insoluble in water. It is insoluble in hydrochloric acid and sulfuric acid, but soluble in nitric acid . In air it is stable up to 800 ° C. Zirconium carbide has a crystal structure of the sodium chloride type with a considerable phase width (ZrC _0.99 -ZrC _0.55 ). It has a Vickers hardness of 25.5 GPa and a modulus of elasticity of 350 to 440 GPa. With halogens it forms tetrahalides at temperatures above 250 ° C. Like titanium carbide, it forms solid solutions with oxygen and nitrogen.

use

In contrast to titanium carbide, zirconium carbide, despite its good properties, is only used for coatings on fuels in atomic and fusion reactors. The reason may be its high price and the difficulty of removing impurities from it.

Individual evidence

↑ ^a ^b ^c ^d ^e ^f ^g ^h Data sheet Zirconium carbide, 99.5% (metals basis excluding Hf), Hf <200ppm from AlfaAesar, accessed on June 10, 2013 ( PDF )(JavaScript required) .
^ ^A ^b Dale L. Perry: Handbook of Inorganic Compounds, Second Edition . Taylor & Francis US, 2011, ISBN 1-4398-1462-7 , pp. 472 ( limited preview in Google Book search).
↑ ^a ^b ^c Georg Brauer (ed.), With the collaboration of Marianne Baudler a . a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume II, Ferdinand Enke, Stuttgart 1978, ISBN 3-432-87813-3 , p. 1387.
^ ^A ^b ^c Hugh O. Pierson: Handbook of Chemical Vapor Deposition, 2nd Edition: Principles, Technology ... William Andrew, 1999, ISBN 0-08-094668-2 , pp. 256 ( limited preview in Google Book Search).
^ Hugh O. Pierson: Handbook of Refractory Carbides & Nitrides: Properties, Characteristics ... William Andrew, 1996, ISBN 0-08-094629-1 , pp. 73 ( limited preview in Google Book search).

[Alfa-1] ↑ ^a ^b ^c ^d ^e ^f ^g ^h Data sheet Zirconium carbide, 99.5% (metals basis excluding Hf), Hf <200ppm from AlfaAesar, accessed on June 10, 2013 ( PDF )(JavaScript required) .

[Dale_L._Perry-2] A ^b Dale L. Perry: Handbook of Inorganic Compounds, Second Edition . Taylor & Francis US, 2011, ISBN 1-4398-1462-7 , pp. 472 ( limited preview in Google Book search).

[brauer-3] Georg Brauer (ed.), With the collaboration of Marianne Baudler a . a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume II, Ferdinand Enke, Stuttgart 1978, ISBN 3-432-87813-3 , p. 1387.

[Hugh_O._Pierson_Vapor-4] A ^b ^c Hugh O. Pierson: Handbook of Chemical Vapor Deposition, 2nd Edition: Principles, Technology ... William Andrew, 1999, ISBN 0-08-094668-2 , pp. 256 ( limited preview in Google Book Search).

[Hugh_O._Pierson_Carbides-5] Hugh O. Pierson: Handbook of Refractory Carbides & Nitrides: Properties, Characteristics ... William Andrew, 1996, ISBN 0-08-094629-1 , pp. 73 ( limited preview in Google Book search).