Silicon nitride (Si3N4) is a high-melting-point ceramic material that is extremely hard and relatively chemically inert. Si3N4 is as light as silicon carbide (SiC), but has excellent thermal shock resistance. Its high fracture toughness makes it resistant to impacts and shocks. The material is prepared by heating powdered silicon between 1300 °C and 1400 °C in an atmosphere of nitrogen. Then the powder of silicon nitride can be sintered to designed shape. As one of the most thermodynamically stable technical ceramic materials with high hardness as well, silicon nitride ceramic is ideal for bearing parts, especially for those required to work at high speed and high temperature.
Color: Gray and Gray-black
Density: 3.2~3.25 g/cm3
Hardness: HRA 92~94
Highest Operating Temperature: 1300 ~1600 ℃
Thermal Conductivity: 23-25 W.(M.K)-1
Bending Strength: ≥ 900 Mpa
Fracture Toughness: 6~8 (Mpa.m1/2)
Thermal Expansion Coefficient (at 0~1400℃): 2.95~3 ×10-6/℃
* Reaction-Bonded Silicon Nitride (RBSN)
* Hot Pressed Silicon Nitride (HPSN)
* Sintered Reaction-Bonded Silicon Nitride (SRBSN)
* Sintered Silicon Nitride (SNN)
Related article: 4 Types of Silicon Nitride Ceramics
Si3N4 bearing balls have already been applied in automobiles, rockets high speed engines, equipment working in corrosive environment and some performance model cars. Compared with steel, high performance ceramic balls have better mechanical properties under high temperature and could survive from most of corrosive chemicals.
Silicon nitride has also been used in high-temperature applications. It was considered as one of the few monolithic ceramic materials that could survive the severe thermal shock and thermal gradients generated in hydrogen-oxygen rocket engines.
Advanced Ceramic Materials is a leading supplier of silicon nitride ceramic products of the highest quality for a wide range of applications. We are happy to provide advice on materials, design, and application. Feel free to contact us for any questions about Si3N4 or other ceramic materials that are not listed on the website.