Silicon nitride ceramic is an inorganic material ceramic that does not shrink when sintered. The strength of silicon nitride is very high, especially hot-pressed silicon nitride, which is the hardest silicon nitride ceramic in the world. In the early stage of application, it is mainly used in machinery, metallurgy, chemical industry, aviation, semiconductor, medical and other industries, as some equipment Or parts of the product, achieved very good expected results. In recent years, with the development of manufacturing technology and testing and analysis technology, the reliability of silicon nitride ceramic products has been continuously improved, so the application area is constantly expanding. What is particularly appreciated is that the silicon nitride ceramic engine is being developed, and great progress has been made, which has become a major event that has attracted worldwide attention in science and technology.

Silicon nitride ceramics have high mechanical strength and hardness close to that of corundum, which is its characteristic. In addition, it has low density and small specific gravity, which is only 2/5 of that of steel, and has good electrical insulation. This also determines that silicon nitride ceramics cannot be processed by common metal processing methods.

Secondly, it is necessary to clarify that silicon nitride ceramics can be machined to achieve the required shape, precision, and surface finish. Due to the high hardness and high brittleness of ceramic materials, it is difficult for mechanical processing to process engineering ceramic components with complex shapes, high dimensional accuracy, low surface roughness, and high reliability.

Silicon nitride ceramics are an important structural material. It is a superhard material with lubricity and wear resistance. It does not react with other inorganic acids except hydrofluoric acid, and has strong corrosion resistance and oxidation resistance at high temperatures. Plus, it resists hot and cold shocks. It can be heated to more than 1000 in the air, and it will not decompose after rapid cooling and rapid heating. It is precisely because Si3N4 ceramics have such excellent characteristics. People often use it to make mechanical parts, such as bearings, gas turbine blades, mechanical seal rings, permanent molds, etc. If the heating surface of the engine components is made of high-temperature-resistant, heat-transfer silicon nitride ceramics , it can not only improve the quality of the diesel engine, save fuel, but also improve thermal efficiency.