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Chromium ( Cr )

Material Information

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Bar Foil Lump Microfoil Powder Rod Single Crystal Sputtering Target
Bar Foil Lump Microfoil Powder Rod Single Crystal Sputtering Target

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General Description:  

Discovered in 1780 by N.L. Vanquelin in Paris, France.

Chromium is a bright, blue/white metal with excellent corrosion resistance. It is obtained by the aluminium reduction of Cr2O3, the source of which is chromite, a double oxide of chromium and iron which generally also contains magnesium. It has an abundance within the earth's crust of approximately 100 ppm. Chromium is soluble in HCl and H2SO4, but not in H3PO4, HNO3 or HClO4 due to the formation of a stable and insoluble oxide layer on its surface; this, along with its hardness, has been used to advantage in the chromium plating of steel which has good corrosion resistance. Chromium is alloyed with nickel in the manufacture of heat resisting alloys, and with iron, or nickel and iron, to produce stainless and heat resistant steels.

Chromium is an important trace element for humans as it assists in the manufacture of glucose.

   

Atomic Properties

Atomic number 24
Atomic radius - Goldschmidt ( nm ) 0.128
Atomic weight ( amu ) 51.996
Crystal structure Body centred cubic
Electronic structure Ar 3d5 4s1
Ionisation potential No. eV
1 6.77
2 16.5
3 31.0
4 49.1
5 69.3
6 90.6
Natural isotope distribution Mass No. %
50 4.35
52 83.79
53 9.50
54 2.36
Photo-electric work function ( eV ) 4.4
Thermal neutron absorption cross-section ( Barns ) 3.1
Valences shown 2, 3, 6

Electrical Properties

Electrical resistivity @20C ( µOhmcm ) 13.2
Temperature coefficient @0-100C ( K-1 ) 0.00214

Mechanical Properties

Material condition Soft Hard Polycrystalline
Bulk modulus ( GPa )     160.2
Hardness - Vickers 130 220
Poisson's ratio     0.21
Tensile modulus ( GPa )     279
Tensile strength ( MPa ) 103 689

Physical Properties

Boiling point ( C ) 2672
Density @20C ( g cm-3 ) 7.1
Melting point ( C ) 1857

Thermal Properties

Coefficient of thermal expansion @0-100C ( x10-6 K-1 ) 6.5
Latent heat of evaporation ( J g-1 ) 6580
Latent heat of fusion ( J g-1 ) 260
Specific heat @25C ( J K-1 kg-1 ) 518
Thermal conductivity @0-100C ( W m-1 K-1 ) 94

Buy Chromium on-line

We stock and supply the following standard forms:
Bar Foil Lump Microfoil Powder Rod Single Crystal Sputtering Target
Bar Foil Lump Microfoil Powder Rod Single Crystal Sputtering Target

Choose a form to search our on-line catalogue  

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