ilicon nitride  ceramics began in the 1960s ,it is a kind of inorganic substance, chemical formula Si3N4. It is an important structural ceramic material with higher hardness, good lubrication and wear resistance.And it has great cold and hot shock resistance,when Silicon nitride is heated to more than 1000℃ in the air, it couldn’t break even sharp cooling and then sharp heating.

With the development of advanced ceramics, people are not satisfied with the preparation of traditional silicon carbide ceramics, in recent years, all kinds of silicon carbide ceramics as the multiphase ceramics have appeared, they greatly improve the performance and are more widely used in ceramic ball bearings, valves, semiconductor materials, measuring instruments, aerospace and other fields.

1. Silicon carbide ceramic ball

Precision ball is an important component in roundness meter, gyro, bearing and precision measurements,and It plays a very important role in precision equipment and precision machining as the benchmark of precision measurements. At present, the precision ball is mainly made of metal materials, but there are some problems such as poor wear resistance and large deformation affected by temperature.however,the ceramic ball are welcome because of its light weight, high hardness, wear resistance, high temperature resistance, corrosion resistance, thermal expansion coefficient and other advantages, Silicon carbide ceramic ball has been widely used in precision bearings and other parts.

1. Silicon carbide abrasive tools

Silicon carbide hardness is very large which can be made to the grinding wheels, sandpaper and abrasive,they are mainly used in machining industry. The hardness of silicon carbide is 9.2 ~ 9.6, second only to diamond and boron carbide, and it is a common abrasive.

1. Silicon carbide matrix composites

Due to the inherent brittleness of ceramic materials, it limits the development in aerospace and other high-tech fields, so much attention is paid to the study of toughening silicon carbide materials. By using sic braided toughening, not only improve the toughness of ceramic materials, but also the strength and modulus of materials in different degrees. Silicon carbide matrix composites have been widely used in high temperature thermal structure in aerospace field due to their high toughness, high strength and excellent oxidation resistance.