Silicon Carbide

Silicon CarbideSilicon Carbide (SiC) combines high thermal conductivity with extreme hardness, wear resistance, thermal shock resistance with a weight half that of steel. These features make Silicon Carbide perfectly suited for seal faces and high performance pump components. Silicon Carbide is available in several forms, each with its own unique properties and benefits:

Reaction Bonded Silicon Carbide: has a coarse grain and low production costs. This produces a material that has a lower hardness but with a high thermal conductivity.

Direct Sintered Silicon Carbide: a higher grade that reaction bonded Silicon Carbide and is typically used in applications that require high temperatures.

Chemical Vapour Depostion (CVD) Silicon Carbide® (® Rohm & Haas): a face centred cubic, polycrystalline material that is extremely pure with a thermal conductivity of around 300 W/mK.

Silicon Carbide applications:

  • Automotive parts
  • Valve components
  • Turbine parts & components
  • Bearings, seals & pump parts
  • Heat exchangers
  • Regulator plates
  • Semiconductor manufacturing

Property Value

Chemical Formula SiC

Density 3.1 - 3.2 g/cm3
Hardness 2550 - 2800 Knoop
Modulus of Elasticity 58 - 65 x 106 psi
Flexural Strength 59 - 108 kpsi
Compressive Strength 550 kpsi
Poisson's Ratio 0.11 - 0.17
Fracture Toughness 3 - 3.4 MPa m1/2

Volume Resistivity >1014 Ohm-cm

Coefficient of Thermal Expansion 3.9 - 4.5 x 10-6/°C
Thermal Conductivity 71 - 130 W/mK
Shock Resistance 350°C Diff
Maximum Working Temperature 1650 °C