Silicon Nitride (Si3N4)

Silicon nitride is a non-oxide engineering ceramic material.

It has four common variants, each represented as a separate material. The Material Properties section below shows ranges encompassing all variants. For more specific values, follow the links in the Variant Materials section.

Material Properties

Compressive (Crushing) Strength600 to 2950 MPa (87 to 430 x 103 psi)

Density2.2 to 3.5 g/cm3 (140 to 220 lb/ft3)

Dielectric Constant (Relative Permittivity) At 1 MHz8.0 to 10

Dielectric Strength (Breakdown Potential)18 kV/mm (0.7 V/mil)

Elastic (Young's, Tensile) Modulus140 to 310 GPa (20 to 45 x 106 psi)

Electrical Resistivity Order of Magnitude11 to 12 10x Ω-m

Flexural Strength130 to 810 MPa (19 to 120 x 103 psi)

Fracture Toughness3.1 to 6.2 MPa-m1/2

Maximum Thermal Shock290 to 750 °C (550 to 1380 °F)

Poisson's Ratio0.24 to 0.27

Specific Heat Capacity720 to 800 J/kg-K

Thermal Conductivity12 to 31 W/m-K

Thermal Diffusivity4.8 to 7.6 m2/s

Thermal Expansion2.5 to 3.2 µm/m-K

The length of each bar compares the given value to the highest value in the database.

Further Reading

Handbook of Refractory Carbides and Nitrides: Properties, Characteristics, Processing and Applications, Hugh O. Pierson, 1996

IEC 60672-3: Ceramic and glass-insulating materials - Part 3: Specifications for individual materials

Silicon Nitride and the Sialons, Vivien Mitchell, 1993