Chromium carbide

Crystal structure
	__ Cr __ C
General
Surname	Chromium carbide
other names	Trichrome dicarbide; Chromium (II) carbide;
Ratio formula	Cr 3 C 2
Brief description	gray odorless solid
External identifiers / databases
ECHA InfoCard	100.031.420
PubChem	3650773
Wikidata	Q2616064
properties
Molar mass	180.01 g mol −1
Physical state	firmly
density	6.68 g cm −3 (25 ° C)
Melting point	1890 ° C
boiling point	3800 ° C
safety instructions
GHS labeling of hazardous substances	no GHS pictograms
	no GHS pictograms
H and P phrases	H: no H-phrases
	P: no P-phrases
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Chromium carbide (more precisely trichrome dicarbide) is a ceramic compound of chromium from the group of carbides . In addition to trichrome dicarbide, there are other chromium carbides with Cr ₇ C ₃ and Cr ₂₃ C ₆ .

Occurrence

Chromium carbide occurs naturally in the form of the mineral tongbait .

Extraction and presentation

Chromium carbide can be obtained by reacting chromium (III) oxide with aluminum and carbon .

{\ displaystyle \ mathrm {3 \ Cr_ {2} O_ {3} +6 \ Al + 4 \ C \ longrightarrow 2 \ Cr_ {3} C_ {2} +3 \ Al_ {2} O_ {3}}}

properties

Chromium carbide is a flammable, gray, odorless solid. It has an orthorhombic crystal structure , space group Pnma (space group no. 62) , lattice parameters a = 5.540 Å , b = 2.833 Å, c = 11.49 Å. The carbon atoms are surrounded by chromium atoms in the first coordination sphere in a trigonal-prismatic manner. Template: room group / 62

use

Chromium carbide serves as the basis for corrosion-resistant hard metal alloys.

Individual evidence

↑ ^a ^b ^c ^d Datasheet Chromium carbide, 99.5% (metals basis) from AlfaAesar, accessed on April 9, 2014 ( PDF )(JavaScript required) .
↑ ^a ^b ^c ^d Datasheet Chromium carbide, −325 mesh, 99.5% from Sigma-Aldrich , accessed on April 9, 2014 ( PDF ).
↑ Osvaldo Mitsuyuki Cintho, Eliane Aparecida Peixoto Favilla, José Deodoro Trani Capocchi: Mechanical-thermal synthesis of chromium carbides . In: Journal of Alloys and Compounds . tape 439 , no. 1–2 , July 31, 2007, pp. 189–195 , doi : 10.1016 / j.jallcom.2006.03.102 .
↑ J. Glaser, R. Schmitt, HJ Meyer: New structure refinement and properties of Cr ₃ C ₂ . In: Journal of Nature Research B . 58, 2003, pp. 929-933 ( PDF , free full text). .
↑ Kirsten Bobzin: Surface technology for mechanical engineering . John Wiley & Sons, 2013, ISBN 978-3-527-68147-1 , pp. 425 ( limited preview in Google Book search).

[Alfa-1] Datasheet Chromium carbide, 99.5% (metals basis) from AlfaAesar, accessed on April 9, 2014 ( PDF )(JavaScript required) .

[Sigma-2] Datasheet Chromium carbide, −325 mesh, 99.5% from Sigma-Aldrich , accessed on April 9, 2014 ( PDF ).

[DOI10.1016/j.jallcom.2006.03.102-3] Osvaldo Mitsuyuki Cintho, Eliane Aparecida Peixoto Favilla, José Deodoro Trani Capocchi: Mechanical-thermal synthesis of chromium carbides . In: Journal of Alloys and Compounds . tape 439 , no. 1–2 , July 31, 2007, pp. 189–195 , doi : 10.1016 / j.jallcom.2006.03.102 .

[4] J. Glaser, R. Schmitt, HJ Meyer: New structure refinement and properties of Cr ₃ C ₂ . In: Journal of Nature Research B . 58, 2003, pp. 929-933 ( PDF , free full text). .

[Kirsten_Bobzin-5] Kirsten Bobzin: Surface technology for mechanical engineering . John Wiley & Sons, 2013, ISBN 978-3-527-68147-1 , pp. 425 ( limited preview in Google Book search).