Carbon-carbon vs. Silicon Nitride

Both carbon-carbon and silicon nitride are non-oxide engineering ceramics. There are 12 material properties with values for both materials. Properties with values for just one material (13, in this case) are not shown.

For each property being compared, the top bar is carbon-carbon and the bottom bar is silicon nitride.

Carbon-Carbon Silicon Nitride (Si₃N₄)

Metric UnitsUS Customary Units

Mechanical Properties

Compressive (Crushing) Strength, MPa		240
Compressive (Crushing) Strength, MPa		600 to 2950

Elastic (Young's, Tensile) Modulus, GPa		95
Elastic (Young's, Tensile) Modulus, GPa		140 to 310

Poisson's Ratio		0.32
Poisson's Ratio		0.24 to 0.27

Thermal Properties

Maximum Temperature: Mechanical, °C		2400
Maximum Temperature: Mechanical, °C		1000 to 1330

Specific Heat Capacity, J/kg-K		760
Specific Heat Capacity, J/kg-K		720 to 800

Thermal Conductivity, W/m-K		40
Thermal Conductivity, W/m-K		12 to 31

Thermal Expansion, µm/m-K		4.0
Thermal Expansion, µm/m-K		2.5 to 3.2

Electrical Properties

Electrical Resistivity Order of Magnitude, 10^x Ω-m		-5.0
Electrical Resistivity Order of Magnitude, 10^x Ω-m		11 to 12

Otherwise Unclassified Properties

Density, g/cm³		1.7
Density, g/cm³		2.2 to 3.4

Common Calculations

Stiffness to Weight: Axial, points		31
Stiffness to Weight: Axial, points		34 to 53

Stiffness to Weight: Bending, points		89
Stiffness to Weight: Bending, points		65 to 78

Thermal Diffusivity, mm²/s		31
Thermal Diffusivity, mm²/s		7.5 to 13