What are the performance characteristics and applications of silicon nitride ceramics

Silicon nitride ceramics, as a high-performance inorganic non-metallic material, have shown extensive application potential in many fields due to their unique physical and chemical properties.

Performance characteristics of silicon nitride ceramics
High strength and high hardness
Silicon nitride ceramics, especially hot pressed silicon nitride, are considered one of the hardest substances in the world. Its compressive strength can exceed 500MPa in high temperature environments, and the bending strength of some high-end products can even reach 900MPa to 1000MPa. This high strength and hardness make silicon nitride ceramics perform well in environments with high loads and wear.
High temperature resistance
Silicon nitride ceramics have extremely high thermal stability, with a decomposition temperature of 1800 ℃ in air and up to 1850 ℃ under specific conditions. Even if heated at a high temperature of 1000 ℃ and quickly poured into cold water, it will not rupture. This excellent heat shock resistance makes silicon nitride ceramics have a wide range of application prospects in high-temperature environments.
corrosion resistance
Silicon nitride ceramics have good resistance to chemical corrosion, able to withstand almost all inorganic acids and less than 30% caustic soda solutions, as well as corrosion from many organic acids. This corrosion resistance enables silicon nitride ceramics to maintain stable performance even in harsh environments.
low-density
Compared with other structural materials, silicon nitride ceramics have a lower specific gravity, which is very advantageous for reducing the weight of components. Silicon nitride ceramics have significant advantages in fields such as aerospace and automotive that require lightweighting.
high-thermal conductivity
The low thermal expansion coefficient and high thermal conductivity of silicon nitride ceramics make them excellent in heat dissipation. Especially in high-power density electronic devices such as semiconductor packaging and electric vehicle control systems, silicon nitride ceramic substrates can effectively reduce chip temperature, improve system stability and reliability.

Application of Silicon Nitride Ceramics
aerospace field
Silicon nitride ceramics have important applications in the aerospace field. As a transparent material, porous silicon nitride ceramics have the advantages of low density, high strength, high temperature resistance, and low dielectric constant, and are suitable for manufacturing components such as radar antenna covers and missile nose cones.
Automotive field
In the automotive field, the application of silicon nitride ceramics is becoming increasingly widespread. For example, the electronic control system in electric vehicles uses silicon nitride ceramic substrates to solve the heat dissipation problem of high-power density electronic devices. In addition, the application of silicon nitride ceramic bearings in motor output shafts has also improved the performance and lifespan of motors.
Semiconductor field
In the field of semiconductor packaging, silicon nitride ceramics have become a key material for improving the stability and reliability of semiconductor devices due to their excellent thermal conductivity and insulation properties. With the development of power electronic devices towards high voltage, high current, and high power density, the application of silicon nitride ceramics will become more widespread.
Mechanical field
Silicon nitride ceramics are also widely used in the mechanical field. Its excellent mechanical properties such as high temperature resistance, acid and alkali corrosion resistance, and self-lubricating make it an ideal material for manufacturing high-precision and high load mechanical components.
Biopharmaceutical field
In the field of biopharmaceuticals, silicon nitride ceramics are used to manufacture medical devices such as artificial joints due to their excellent biocompatibility. This application not only improves the performance and lifespan of medical devices, but also reduces the pain and risk for patients.
5G communication equipment
With the rapid development of 5G communication technology, silicon nitride ceramics have become an excellent material for 5G mobile phone backboards due to their excellent wave transmission and thermal conductivity. In addition, DPC (Direct Plated Copper) ceramic plates also use silicon nitride ceramics as substrates, providing better signal transmission and higher reliability for 5G communication equipment.

Silicon nitride ceramics have shown wide application prospects in multiple fields due to their unique performance characteristics. With the advancement of technology and the continuous expansion of the market, the application scope of silicon nitride ceramics will further expand.