Silicon nitride is an important structural ceramic material. It is a superhard substance, lubricious in itself, and wear-resistant, and is an atomic crystal; it resists oxidation at high temperatures. Moreover, it can also resist cold and heat shocks, and it will not shatter when heated to above 1000°C in the air, cooled rapidly and heated again sharply. Use it to make bearings, gas turbine blades, mechanical seal rings, permanent molds and other mechanical components. Therefore, it is mostly used to manufacture mechanical components such as bearings, gas turbine blades, mechanical seal rings, and permanent molds. Silicon nitride ceramics have high hardness and wear resistance, and have a very low coefficient of friction. It can be said that the surface is very smooth and does not require professional polishing.

　　As an excellent high-temperature engineering material, silicon nitride ceramic material can best exert its advantages in its application in high-temperature fields. The future development direction of Si3N4 is: ⑴ make full use of the excellent characteristics of Si3N4 itself; ⑵ develop some new fluxes, research and control the best components of existing fluxes during sintering of silicon nitride powder; ⑶ improve Powder making, molding and sintering process; ⑷Develop the compounding of materials such as Si3N4 and SiC, so as to produce more high-performance composite materials. The application of Si3N4 ceramics in automobile engines has created a new situation for the development of new high-temperature structural materials. The automobile industry itself is a multidisciplinary industry integrating various technologies. China is an ancient civilization with a long history. It has made brilliant achievements in the history of ceramic development. With the process of reform and opening up, one day China will also It is bound to rank among the world's largest auto industry countries and create greater glories for the development of ceramics.

　　Silicon nitride ceramics are extremely resistant to high temperatures, and their strength can be maintained at a high temperature of 1200°C without falling. They will not melt into a melt after being heated, and will not decompose until 1900°C. The acid-free machine and the caustic soda solution below 30% are also resistant to the corrosion of many organic acids; at the same time, it is a high-performance electrical insulating material.