Silicon nitride and silicon nitride ceramics Silicon nitride is an inorganic substance with the chemical formula Si3N4. It is an important structural ceramic material with high hardness, inherent lubricity, and wear resistance. It is an atomic crystal; it is resistant to oxidation at high temperatures. Moreover, it can resist the impact of cold and heat. It will not be broken if it is heated to above 1000°C in the air, cooled rapidly and then heated rapidly. It is precisely because of the excellent characteristics of silicon nitride ceramic that people often use it to manufacture mechanical components such as bearings, turbine blades, mechanical seal rings, permanent molds, and so on. If silicon nitride ceramics, which are resistant to high temperature and difficult to transfer heat, are used to make the heating surface of engine parts, it can not only improve the quality of engines, save fuel, but also improve thermal efficiency. Functions and applications of silicon nitride Silicon nitridehas a unique grain structure, high strength, toughness and very good thermal resistance. It is an ideal choice for applications with high dynamic stress, thermal stress and high reliability requirements. This unique combination of material properties offers advantages in harsh environment applications such as turbines and high-end ball bearings. The main function
Wear resistance, corrosion resistance, high mechanical strength and toughness, electrical insulation, thermal shock resistance Application
Wear-resistant parts, semiconductor manufacturing equipment components, high-temperature parts
Are there any disadvantages in the production and application of silicon nitride ceramics?
Although silicon nitride has good properties, it also has the common property of ceramics—brittleness. Silicon nitride ceramics are polycrystalline sintered bodies composed of ionic or covalently bonded crystal grains. The highly directional chemical bond determines the low density of grain dislocations in the ceramics, less slip systems, and low energy for crack growth. In the fracture process, besides the addition of new fracture surface energy, there is almost no other energy dissipation mechanism, which leads to shortcomings such as low strength and insufficient toughness. The fatal weakness of brittleness makes it impossible to guarantee the reliability in the application. Therefore, improving its toughness and improving its reliability has always been an important research direction of silicon nitride ceramics. Why is the cost of silicon nitride ceramics so high?
1. The cost of powder is high.
Powder preparation requires high-purity silicon powder and nitrogen, and the nitriding process requires strict control of temperature, time and air pressure. The prepared powder can be ground with high energy. The whole process has high technical requirements. To achieve high purity, Nano-level particle size, and high proportion of phase purity, the requirements for equipment, technology and even quality management are very high.
2. Silicon nitride ceramics are expensive.
1) High sintering cost. Silicon nitride sintering generally has three methods, reaction sintering, pressure less sintering and pressure sintering. From the perspective of ceramics evaluation, the quality of the three methods increases sequentially. The three methods have their own advantages. The higher the quality of ceramics, the higher the requirements for equipment, technology and management, the higher the cost.
2) High processing cost. Silicon nitride has a very high hardness and needs to be processed with diamond abrasives. If special shape processing is required, special equipment is required. Therefore, silicon nitride products are more expensive.
TRUNNANO (aka. Luoyang Tongrun Nano Technology Co. Ltd.) is a trusted global chemical material supplier & manufacturer with over 12 years’ experience in providing super high-quality chemicals and Nanomaterials. Thesilicon nitrideproduced by our company has high purity, fine particle size and impurity content. Please contact usif necessary.
