Silicon nitride ceramics is a class of materials with the best comprehensive performance in the structural ceramics family, and is considered to be one of the most promising high-temperature structural ceramic materials for development and application. Silicon nitride ceramics have high flexural strength and fracture toughness, such as silicon nitride ceramics prepared by hot pressing sintering, at room temperature, the flexural strength can reach 800-1050MPa, and the fracture toughness can reach 6-7MPa m1/2 , and has good wear resistance and certain self-lubricating ability. Therefore, silicon nitride is well suited for bearing material applications. In addition, silicon nitride ceramics also have a relatively high theoretical thermal conductivity, which makes it considered as a potential heat dissipation and packaging material for high-speed circuits and high-power devices.
In recent years, how to prepare high-performance silicon nitride ceramics has always been a hot spot in the research of structural ceramics at home and abroad. There are many factors affecting the preparation of high-performance silicon nitride ceramics. For example, the silicon nitride powder used for sintering, the selection of sintering aids and additives, and the sintering method can all affect the performance of high-performance silicon nitride ceramics to a certain extent. This paper discusses the preparation process and research status of high-performance silicon nitride ceramics, and discusses the main application progress of high-performance silicon nitride ceramics.

Compared with other ceramic materials, silicon nitride ceramics have many excellent characteristics, such as high theoretical thermal conductivity, good chemical stability, non-toxicity, high flexural strength and fracture toughness, etc. At present, in the research reports on high thermal conductivity silicon nitride ceramics, the thermal conductivity can reach up to 177W·m ^-1 ·K ^-1 , and the mechanical properties are relatively excellent (bending strength reaches 460MPa, fracture toughness reaches 11.2MPa m ^1/2 ). These characteristics make it considered as a potential heat dissipation and packaging material for high-speed circuits and high-power devices.