Silicon Nitride Rod is a premium ceramic material widely used in the metallurgical industry, renowned for its exceptional performance in high-temperature environments. Its unique microstructure provides excellent thermal shock resistance, superior creep and oxidation resistance, low thermal conductivity, and high wear resistance, making it ideal for demanding industrial applications.
Five production methods are available: SRBSN, GPSN, HPSN, HIP-SN, and RBSN, with GPSN being the most commonly used for manufacturing Silicon Nitride components.
Originally developed for advanced gas turbines, ceramic rollers in bearings now serve critical roles in machine tool spindles, motors, generators, and various industrial applications. Hybrid rolling bearings with ceramic rollers are extensively used in challenging environments such as railways and renewable energy industries, particularly in wind turbines.
| Property | Item | 99% Alumina | 99.8% Alumina | Zirconia Ceramics | Silicon Nitride | Silicon Carbide | Unit |
|---|---|---|---|---|---|---|---|
| Mechanical Characteristics | Color | light yellow | White | Ivory | Black Grey | Black | |
| Bulk Density | 3.85 | 3.93 | 6.02 | 3.2 | 3.16 | g/cm³ | |
| Bending Strength | 310 | 370 | 800 | 750 | 450 | MPa | |
| Compressive Strength | 2,400 | 2500 | 3000 | 3800 | 3900 | MPa | |
| Vickers Hardness | 1,600 | 1850 | 1200 | 1700 | 2800 | HV 0.5 | |
| Fracture Toughness | 3~4 | 4 | 8 | 7 | 3.5 | MPa m¹/² |
Automotive Industry: Used in engine components including rocker pads, turbochargers, and waste gas control valves for improved performance and acceleration.
Bearings: Silicon nitride ball bearings offer superior impact resistance and are used in high-performance applications including NASA space shuttles, automotive bearings, wind turbines, and industrial machinery.
Metal Cutting Tools: Utilized for high-speed machining of cast iron, hard steel, and nickel-based alloys due to exceptional hardness, thermal stability, and wear resistance.
Electronics: Serves as superior insulation and chemical barrier in integrated circuits, providing excellent protection against corrosion and instability in microelectronics.
| Properties | Units | Silicon Nitride |
|---|---|---|
| Mechanical | ||
| Density | gm/cc | 3.2 |
| Flexural Strength | MPa | 830 |
| Compressive Strength | MPa | 2500 |
| Hardness | kg/mm² | 1580 |
| Thermal | ||
| Heat Conductivity | W/m·K | 30 |
| Coefficient of Thermal Expansion | 10⁻⁶/K | 3.3 |
| Max Use Temperature | °C | 1400 |
| Electrical | ||
| Dielectric Constant | / | 8 |
| Volume Resistivity | ohm·cm | >10¹⁴ |