Area of application
·
the hour industry (hour glasses),
·
optics(windows , lenses),
·
optoelectronics,
·
microelectronics,
·
semi-conductor techniques,
·
epitaxially structures,
·
the chemical industry,
·
components of mechanical engineering,
·
the copy industry (scanners),
·
substrates for reception epitaxially
structures on the basis of nitride of gallium,
·
the jeweler industry (largely dimensional jewels),
·
laser technique (as casings for gas lasers),
·
medicine - orthopedy, stomatology.
Physical and chemical properties
Parameters
|
Values
|
The chemical formula
|
a- Al2O3
|
Molecular weight
|
101.96
|
Specific density
|
3.96-4.10g/cm3
|
Crystal system
|
Dithregonal-scalenohedral
|
Temperature of fusion
|
2050 оС
|
Mohs hardness:
|
9
|
Knoop hardness:
|
|
^ axis С
|
1800-2200 kg/mm2
|
II axis С
|
1175-1380 kg/mm2
|
Factor
of refraction
|
1.753-1.760
|
Specific
thermal capacity
|
0.8 cal/degree оС
|
Thermal conduction
|
0.01 cal/sec. cm. degree. оС
|
Optical type
|
uniaxial, negative
|
Solubility
|
steady in sour and alkaline environments
|
Machinability
|
well ground, polished, forming a smooth surface
|
The maximal temperature of application
|
1850-1920 оС
|
Toxicity
|
not
toxic
|
Fire hazard
|
not flammable
|
Explosion
hazard
|
not
explosive
|
The maximal sizes
|
250х145х30mm
|
|