Silicon Nitride (Si3N4)
Silicon nitride ceramic has low thermal expansion coefficient, high thermal conductivity and excellent thermal shock resistance. In the very high temperature, silicon nitride keeps a high strength and impact resistance. As an excellent high temperature engineering materials, silicon nitride ceramics are “super hard” providing a high mechanical strength, outstanding wear and very good acid /alkali corrosion resistance. The material is self lubricated.
Applications
- Low-pressure cast aluminum industry: heating body protection tube, lift tube
- The photovoltaic industry: long crystal crucible, exhaust hood, heat shield
- The bearing industry: precision bearings ball, roller
- Others: mold holder, fusion furnace support, crucible rack, nozzle, insulation ring etc…
Advantages
- High mechanical strength
Silicon nitride keeps high mechanical strength over a wide temperature range. The outstanding strength characteristics with relatively low density make it easy to handle compared to conventional materials.
- Chemical stability
Silicon nitride is inert against molten metal even at high temperatures. It ensures longer work-life with minimum maintenance.
- Superior thermal shock resistance
Silicon nitride has exceptional high thermal shock resistance – making it ideal for applications with high dynamic stresses, thermal rigor, and demanding reliability requirements
Technical Characteristics – Silicon Nitride (Si3N4)
| High purity Si3N4 | HS-100 | HS-200 |
| Color | Grey | Black |
| Porosity | ≤0.4 | ≤0.4 |
| Density（g/cm3） | 3.2 | 3.2 |
| Elastic Modulus（GPa） | 320 | 300 |
| Flexural strength Room（MPa） | 780 | 700 |
| Poisson’s ratio | 0.26 | 0.26 |
| Hardness (Hv) | 1800 | 1500 |
| Thermal expansion（10-6/K） | 3.1 | 3.2 |
| Thermal Conductivity (W/m•K) | 20 | 35 |
| Max. operating temperature Air (℃) | 1200 | 1200 |
| Max. operating temperature Inert Gas (℃) | 1500 | 1500 |
| Thermal shock resistance (K) | 600 | 700 |
| Resistivity（Ω•cm） | ＞1014 | ＞1014 |
| Corrosion resistance | Good | Good |
