Four major application areas of silicon nitride ceramics

Mechanical Field

Silicon nitride ceramics are mainly used as valves, pipes, classification wheels, and ceramic cutting tools in the mechanical industry. The most widespread application is silicon nitride ceramic bearing balls. Silicon nitride ceramics are widely recognized as the best bearing material, and the most critical “core player” in bearings—silicon nitride ceramic bearing balls—are the true “unsung heroes” that support equipment performance. These small ceramic balls, ranging in diameter from a few millimeters to tens of millimeters, may seem insignificant, but with their “lightweight, hard, stable, and insulating” properties, they play a “key role” in new energy vehicles, roller skates, dental drills, and even high-end bicycles.

Aerospace Field

Silicon nitride ceramic materials have advantages such as high strength, high temperature resistance, and good chemical stability, which can meet the stringent requirements for materials in the aerospace field. Silicon nitride ceramics have two classic applications in the aerospace field: firstly, silicon nitride is considered one of the few monolithic ceramic materials capable of withstanding the severe thermal shock and thermal gradients generated by hydrogen/oxygen rocket engines, and is used in rocket engine nozzles; secondly, the excellent properties of silicon nitride ceramics and their composites, such as heat resistance, wave transmission, and load-bearing capacity, make them one of the new generation of high-performance wave-transmitting materials under research.

Semiconductor Field

As electronic devices develop towards miniaturization and high performance, semiconductor packaging requires higher demands on heat dissipation materials. Silicon nitride ceramics have a thermal conductivity of up to 90-120 W/(m·K), and a high degree of matching with the thermal expansion coefficient of third-generation semiconductor substrate SiC crystals, making them the preferred material for SiC power device packaging substrates. Internationally, Japanese companies such as Toshiba and Kyocera dominate the market, while domestic companies such as Sinoma Advanced Materials have achieved technological breakthroughs.

In addition to being a key packaging material, silicon nitride ceramics show broad application prospects in semiconductor manufacturing equipment. In the wafer processing process, silicon nitride ceramics can be used to manufacture high-temperature resistant and thermal shock resistant heating elements, meeting the stringent operating conditions of equipment such as CVD (chemical vapor deposition) and diffusion furnaces.

Biomedical Field

As an emerging bioceramic material, silicon nitride shows great application potential in medical implants due to its excellent mechanical properties and biocompatibility. Specifically, silicon nitride has been used as an orthopedic biomaterial and successfully applied in bearing components of prosthetic hip and knee joints to improve wear resistance and extend the lifespan of the prostheses. Furthermore, silicon nitride materials have been used to promote bone fusion in spinal surgery. Silicon nitride ceramic materials demonstrate excellent stability and reliability in the medical field. Silicon nitride also exhibits strong cell adhesion and osteoconductivity, providing an important biological basis for its application in bone repair. However, the inherent brittleness of silicon nitride ceramics remains a major challenge for its application in bone repair engineering. In addition, silicon nitride materials are difficult to degrade in vivo, which hinders the growth of new bone tissue into the repair site and its complete replacement of the original repair material, thus limiting the breadth of its clinical applications.