|
CHROMIUM
(Cr)
GENERAL
PROPERTIES
|
Symbol:
|
Cr
|
|
Atomic
Number:
|
24
|
|
Atomic
Weight:
|
51.996
|
|
Density:
|
7.18
gm/cc
|
|
Melting
Point:
|
1857
oC
|
|
Boiling
Point:
|
2672
oC
|
|
Thermal
Conductivity:
|
0.939
W/cm/oK
@ 298.2 oK
|
|
Electrical
Resistivity:
|
12.9
microhm-cm @ 0 oC
|
|
Electronegativity:
|
1.6
Paulings
|
|
Specific
Heat:
|
0.107
Cal/g/oK
@ 25 oC
|
|
Heat
of Vaporization:
|
72.97
K-cal/gm atom at 2672 oC
|
|
Heat
of Fusion:
|
3.66
Cal/gm mole
|
MATERIAL
OVERVIEW
Characteristics:
Hard brittle semi-gray metal. Compounds have strong
and varied colors. Cr ion forms many coordination
compounds. Exists in active and passive forms the
latter giving rise to its corrosion resistance due to
a thin surface oxide layer that passivates the metal
when treated with oxidizing agents. Active form reacts
readily with dilute acids to form chromous salts.
Soluble in acids (except nitric) and strong alkalies;
insoluble in water.
Derivation:
From chromite (q.v.) by direct reduction
(ferrochrome); by reducing the oxide with finely
divided aluminum or carbon; and by electrolysis of
chromium solutions.
Hazard:
Hexavalent chromium compounds have an irritating and
corrosive effect on tissue resulting in ulcers and
dermatitis on prolonged contact. Tolerance for
chromium dust and fume is 0.5 mg/m3 of air. It is a known carcinogen (OSHA).
TYPICAL
ANALYSES
Impurities
in ppm
|
Material
/ Purity:
|
2N4
|
3N+
|
5N
|
|
Al
|
600
|
-
|
-
|
|
Co
|
10
|
150
|
-
|
|
Cu
|
-
|
10
|
<1
|
|
Pb
|
-
|
10
|
-
|
|
S
|
100
|
300
|
-
|
|
Mn
|
-
|
-
|
<1
|
|
Na
|
-
|
-
|
1
|
|
Fe
|
2600
|
100
|
-
|
|
Mg
|
-
|
-
|
1
|
|
Si
|
1000
|
-
|
-
|
ROD
|
Material
|
Purity
|
|
Chromium
Rod .125”
|
3N+
|
|
Chromium
Rod .250”
|
3N+
|
|
Chromium
Rod .500”
|
3N+
|
|
Chromium
Rod .625”
|
3N+
|
|
Chromium
Rod .750”
|
3N+
|
|
Chromium
Rod 1”
|
3N+
|
Rod
is cut to order and sold by the inch or foot.
SPUTTERING TARGETS
|
Material
|
Purity
|
|
Chromium
Sputtering Target
2"D X .125"T
|
3N+
|
|
Chromium
Sputtering Target 2"D X .250"T
|
3N+
|
|
Chromium
Sputtering Target
3"D X .125"T
|
3N+
|
|
Chromium
Sputtering Target 3"D X .250"T
|
3N+
|
|
Chromium
Sputtering Target 4"D X .125"T
|
3N+
|
|
Chromium
Sputtering Target 4"D X .250"T
|
3N+
|
|
Chromium
Sputtering Target 5"D X .125"T
|
3N+
|
|
Chromium
Sputtering Target 5"D X .250"T
|
3N+
|
|
Chromium
Sputtering Target 6"D X .125"T
|
3N+
|
|
Chromium
Sputtering Target 6"D X .250"T
|
3N+
|
Additional
sizes and sputtering targets produced from compounds
are available
upon request.
POWDER, SHOT, PELLETS, & INGOT
|
Material
|
Purity
|
|
Chromium
Flake, Electrolytic 1” by Down
|
5N
|
|
Chromium
Granules 2-5mm
|
5N
|
|
Chromium
Pellets .250"D X .250"L
|
4N5
|
|
Chromium
Powder, -60 Mesh
|
4N
|
|
Chromium
Powder-100 Mesh
|
3N
|
|
Chromium
Powder-325 Mesh
|
3N
|
Powder,
shot, pellets, and ingots are packaged to order and
sold by the gram or kilogram.
COMPOUNDS
|
Material
|
Purity
|
|
Chromium
Antimonide CrSb -100 Mesh
|
2N
|
|
Chromium
Arsenide Cr2As
-60 Mesh
|
2N
|
|
Chromium
Boride CrB -150 +325 Mesh
|
2N5
|
|
Chromium
Boride CrB -325 Mesh
|
2N5
|
|
Chromium
Boride CrB2
-150 +325 Mesh
|
2N5
|
|
Chromium
Boride CrB2
-325 Mesh
|
3N
|
|
Chromium
Boride Cr5B3
-325 Mesh
|
2N5
|
|
Chromium
Boride Cr2B
-325 Mesh
|
2N5
|
|
Chromium
Bromide CrBr3
1/4" Pieces by Down
|
2N
|
|
Chromium
Carbide Cr3C2
-200 +325 Mesh
|
2N5
|
|
Chromium
Carbide Cr3C2
-325 Mesh
|
2N5
|
|
Chromium
Carbide Cr7C3
-325 Mesh
|
2N5
|
|
Chromium
Chloride CrCl2
-80 Mesh
|
2N5
|
|
Chromium
Chloride CrCl3
1/8" Pieces by Down
|
2N5
|
|
Chromium
Fluoride CrF3
-80 Mesh
|
2N
|
|
Chromium
Iodide CrI3
-60 Mesh
|
2N5
|
|
Chromium
Nitride Cr2N
-325 Mesh
|
2N
|
|
Chromium
Oxide Cr2O3
-325 Mesh
|
| 
