Silicon Nitride

Silicon NitrideSilicon Nitride (Si3N4) provides high thermal shock resistance coupled with a resistance to fracturing. In addition it displays high temperature strength and wear resistance, making it perfectly suited for internal combustion and turbine engine applications.

Silicon Nitride can be manufactured by hot press sintering or preferably using lower temperature methods to avoid dissociation. The sintered material can be worked to produce precise features and high tolerances, usually by diamond grinding.

Silicon Nitride is often considered as one of the most advanced technical ceramics available for extreme applications that require lightness combined with excellent thermal shock resistance and high fracture toughness.

Silicon Nitride applications:

  • Turbocharger components
  • Ball bearings
  • Cutting tools
  • Advanced ceramic tubes
  • Valve components
  • Nozzles
  • Seals, seats and bearings

Property Value

Chemical Formula Si3N4

Density 3.2 - 3.31 g/cm3
Hardness 1500 - 2000 Knoop
Modulus of Elasticity 45 - 49 x 106 psi
Flexural Strength 65 - 132 kpsi
Compressive Strength 435 - 500 kpsi
Poisson's Ratio 0.27
Fracture Toughness 4 - 6 MPa m1/2

Dielectric Strength 450 V/mil
Dielectric Constant 8.4 (@ 1 MHz)
Volume Resistivity >1013 Ohm-cm

Coefficient of Thermal Expansion 3.0 - 3.9 x 10-6/°C
Thermal Conductivity 15 - 30 W/mK
Specific Heat 0.13 cal/g °C
Shock Resistance 750°C Diff
Maximum Working Temperature 1250 °C