Silicon Nitride Material Properties
Silicon Nitride (Si3N4) is one of the toughest ceramic materials. Characteristic properties include high wear resistance, high strength and ductility, and is chemical and thermoschock resistant. At only 40% the weight of steel, its high temperature hardness is twice as hard as steel and retains strength and hardness up to 1800°F. Additionally, it has excellent dielectric properties, high resistivity, a low thermal expansion coefficient and is relatively chemically inert. Silicon Nitride is a good selection for applications that require high heat resistance, low friction, high loads and speed.
Applications for precision balls include: high precision bearings, pumps, compressors, flow meters, metrology instrumentation
Silicon Nitride
| PHYSICAL PROPERTIES | |
|---|---|
| chemical composition | Si3N4 |
| density | 3.23 g/cm2 |
| apparent porosity | >0.5% |
| THERMAL PROPERTIES | |
| thermal expansion coefficient | 3.4 x 10-6/K |
| thermal conductivity | 16-19 W/m·K |
| thermal shock resistance ΔT | 650°C |
| specific heat | 100°C 880 J/kg.K |
| maximum use temperature | 1400°C |
| MECHANICAL PROPERTIES | |
| modulus of rupture | 980 MPa (psi x 103) |
| Young’s modulus | 300 GPa (psi x 106) |
| Poisson’s ratio | 0.29 |
| hardness | 1600 Vickers |
| fracture toughness | 6.0 MPa·m1/2 |
| ELECTRICAL PROPERTIES | |
| electrical resistivity | 1010 Ω |
| dielectric rigidity | 15 Kv/mm |
