Boron Carbide vs. Silicon Nitride
Both boron carbide and silicon nitride are non-oxide engineering ceramics. There are 15 material properties with values for both materials. Properties with values for just one material (7, in this case) are not shown.
For each property being compared, the top bar is boron carbide and the bottom bar is silicon nitride.
Metric UnitsUS Customary Units
Mechanical Properties
| Compressive (Crushing) Strength, MPa | 1710 to 2200 | |
| 600 to 2950 |
| Elastic (Young's, Tensile) Modulus, GPa | 240 to 460 | |
| 140 to 310 |
| Flexural Strength, MPa | 170 to 410 | |
| 130 to 810 |
| Fracture Toughness, MPa-m1/2 | 2.5 to 3.5 | |
| 3.1 to 6.2 |
| Poisson's Ratio | 0.17 to 0.19 | |
| 0.24 to 0.27 |
Thermal Properties
| Maximum Temperature: Mechanical, °C | 1000 to 2500 | |
| 1000 to 1330 |
| Specific Heat Capacity, J/kg-K | 950 | |
| 720 to 800 |
| Thermal Conductivity, W/m-K | 31 to 90 | |
| 12 to 31 |
| Thermal Expansion, µm/m-K | 4.5 to 5.6 | |
| 2.5 to 3.2 |
Electrical Properties
| Dielectric Constant (Relative Permittivity) At 1 MHz | 6.4 | |
| 8.0 to 10 |
| Electrical Resistivity Order of Magnitude, 10x Ω-m | 0 to 11 | |
| 11 to 12 |
Otherwise Unclassified Properties
| Density, g/cm3 | 2.1 to 2.7 | |
| 2.2 to 3.4 |
Common Calculations
| Stiffness to Weight: Axial, points | 63 to 100 | |
| 34 to 53 |
| Stiffness to Weight: Bending, points | 91 to 100 | |
| 65 to 78 |
| Thermal Diffusivity, mm2/s | 16 to 38 | |
| 7.5 to 13 |