Drawing No. EH–MT–022 // Engineering Materials
Silicon Nitride Ceramic Properties
Reviewed August 2026
Silicon nitride combines low density, high stiffness/strength, low thermal expansion and exceptional thermal-shock resistance.
Representative properties
The stated basis, temperature and direction are part of the value. Switch units without changing the physical reference.
What changes these properties?
Engineering variability
- Sintering additives and processing route affect thermal conductivity and high-temperature creep.
- Flexural strength differs from uniaxial tensile strength and should not be substituted directly.
- Mechanical properties remain good at elevated temperature but are product-specific.
- Oxidation and glassy grain-boundary phases can govern long-duration high-temperature use.
Selection note
Used for bearings, turbocharger rotors, molten-metal handling, cutting tools and high-temperature structural components.
Where a property is shown as qualitative rather than numeric, that is intentional: the selected source or the material physics does not justify a single comparable scalar.
How to interpret this material
Stiffness
Young’s modulus describes elastic stiffness. For crystals and composites, orientation can make one scalar modulus only a directional reference.
Strength / failure
Ductile metals can use yield and tensile strength. Brittle ceramics/semiconductors and anisotropic composites require fracture, flexural or directional strength descriptions instead.
Thermal response
Conductivity, heat capacity and expansion are temperature dependent. The last column is a melting or transition descriptor only where that physical concept is appropriate.
Technical sources
The database favors manufacturer, industry, government or academic technical references and labels secondary condition-specific datasets when a primary source does not expose a complete property set.