MakeItFrom.com
Menu (ESC)

Silicon Nitride (Si3N4)

Silicon nitride is a non-oxide engineering ceramic. It can have a moderately low thermal conductivity relative to other non-oxide engineering ceramics in the database.

The properties of silicon nitride include four common variations. The property values on this page show ranges across all of them. For more specific values, follow the links immediately below. The graph bars on the material properties cards further below compare silicon nitride to other non-oxide engineering ceramics (top) and the entire database (bottom).

Mechanical Properties

Compressive (Crushing) Strength

600 to 2950 MPa 87 to 430 x 103 psi

Elastic (Young's, Tensile) Modulus

140 to 310 GPa 20 to 45 x 106 psi

Flexural Strength

130 to 810 MPa 18 to 120 x 103 psi

Fracture Toughness

3.1 to 6.2 MPa-m1/2 2850 to 5610 psi-in1/2

Poisson's Ratio

0.24 to 0.27

Thermal Properties

Maximum Thermal Shock

290 to 750 °C 550 to 1380 °F

Specific Heat Capacity

720 to 800 J/kg-K 0.17 to 0.19 BTU/lb-°F

Thermal Conductivity

12 to 31 W/m-K 7.0 to 18 BTU/h-ft-°F

Thermal Expansion

2.5 to 3.2 µm/m-K

Other Material Properties

Density

2.2 to 3.4 g/cm3 140 to 210 lb/ft3

Dielectric Constant (Relative Permittivity) At 1 MHz

8.0 to 10

Dielectric Strength (Breakdown Potential)

18 kV/mm 0.7 V/mil

Electrical Resistivity Order of Magnitude

11 to 12 10x Ω-m

Common Calculations

Stiffness to Weight: Axial

34 to 53 points

Stiffness to Weight: Bending

65 to 78 points

Thermal Diffusivity

7.5 to 13 m2/s

Followup Questions

Further Reading

Silicon Nitride and the Sialons, Vivien Mitchell, 1993

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