Sapphire properties

   Benefits

  Resistant to high temperatures

   Does not melt at the temperature below 2050°C.

   Retains purity in high-temperature environments

  Rigid and durable

Resistant to scratching by a majority of materials

Resistant to high pressure

Enduring

 Chemically inert, insoluble in the

 majority of conventional industrial

 solutions and corrosion-resistant

Can be used in aggressive environment

Easily washed

Long-life performance

Possess high purity

In some environments operating life of sapphire up to 5 times more than of quartz

 Wide transmittance spectrum in UV,

 visible IR and microwave ranges

  Continuous and stable transmittance of infra-red rays

  Outstanding light transmittance at 0.25 – 4.50 μm

 High thermal conductivity

  Enables rapid heating and cooling

  General

  Chemical formula:

 Al₂O₃

  Growing method:

 Kyropoulos, Stepanov (EFG)

  Structure:

 hexagonal

 a = b = 4.77 A

 c = 13.04 A

  Thermal

  Melting temperature:

 2040 °C

  Linear expansion coefficient:

 6.7 x 10^-6 / °C parallel to С axis

 5.0 x 10^-6 / °C perpendicular to С axis

  Thermal conductivity:

 46.06 W/m °K (0°C)

  Mechanical

  Density:

 3.98 g/cm³

  Hardness:

 Mohs: 9

 Knoop: 1800 daN/mm² parallel to С axis

 2200 daN/mm² perpendicular to С axis

  Tensile strength:

 400 MPa/mm² (25°C) 275 MPa/mm² (500°C) 345 MPa/mm² (1000°C)

  Flexural strength:

 35 to 39 daN/mm²

  Compression stress:

 2.0 GPa

  Young's modulus

 3.6 x 10⁴ to 4.4 x 10⁴ daN/mm²

  Electric

  Dielectric permeability:

 9.3 (10³ - 10⁹ Hz, 25°C) perpendicular to С axis

 11.5 (10³3 - 10⁹ Hz, 25°C) parallel to С axis

  Specific resistivity:

 10¹⁶ Ω/cm (25°C)

 10¹¹ Ω/cm (500°C)

 10⁶ Ω/cm (1000°C)