Industry News

Why silicon nitride is an important structural ceramic material

Views : 141
Author : Lzh
Update time : 2022-12-08 16:32:59
What is silicon nitride?
Silicon nitride is an important structural ceramic material with high hardness, lubricity, and wear resistance. It is an atomic crystal that resists oxidation at high temperatures. It can also withstand cold and hot shocks. It can be heated to more than 1000 in air, cooled sharply, and then heated smartly without breaking. It is precise because silicon nitride ceramics have such excellent characteristics that people often use it to manufacture bearings, turbine blades, mechanical seal rings, Permanent molds, and other mechanical components. Suppose silicon nitride ceramics that are resistant to high temperatures and not easy to heat transfer are used to manufacture the heating surfaces of engine components. In that case, it can improve the quality of middle distillate engines and save fuel and thermal efficiency. China, the United States, Japan, and other countries have developed middle distillate engines.

The production method of silicon nitride
There are two production methods of silicon nitride ceramic products, namely reaction sintering and hot pressing sintering. The reaction sintering method is to form silicon powder or a mixture of silicon powder and silicon nitride powder according to the general production method of ceramic products. Then, in the nitriding furnace, pre-nitriding is carried out at 1150~1200 . After obtaining a particular strength, machining can be carried out on the machine tool. Then, further nitriding is carried out at 1350~1450 for 18~36h until the products become silicon nitride. In this way, the product size is accurate, and the volume is stable. The hot pressing sintering method is to combine silicon nitride powder with a small number of additives, such as MgO, Al2O3, MgF2, AlF3, or Fe2O3, Under the pressure of 19.6 MPa or above and a temperature of 1600~1700 , the products made by hot pressing sintering are usually denser. They have better properties than those made by reaction sintering.
 
Primary applications of silicon nitride
Silicon nitride is used as advanced refractories, such as SI3N4-SIC refractories combined with sic for blast furnace stack, and other parts, such as SI3N4-BN materials combined with BN for horizontal continuous casting separation ring. The SI3N4-BN series flat continuous casting separation ring is an acceptable ceramic material with a uniform structure, high mechanical strength, good heat resistance, and impact resistance. It will not be wetted by liquid steel, meeting the process requirements of continuous casting. In addition, silicon nitride ceramic materials have high thermal stability, strong oxidation resistance, and high dimensional accuracy. Silicon nitride is a covalent compound with a high bond strength and can form an oxide protective film in the air, so it also has good chemical stability. It will not be oxidized below 1200 . The protective film generated at 1200~1600 can prevent further oxidation and will not be soaked or corroded by molten metals or alloys such as aluminum, lead, tin, silver, brass, and nickel. Still, it can be corrupted by molten solutions such as magnesium, nickel-chromium alloy, stainless steel, etc.
 
Price of silicon nitride          
Silicon nitride particle size and purity will affect the product's Price, and the purchase volume can also affect the cost of silicon nitride. A large amount of large amount will be lower. The Price of silicon nitride can be found on our company's official website. 

Silicon nitride supplier
Luoyang Tongrun Nano Technology Co. Ltd.  (TRUNNANO) Luoyang City, Henan Province, China, is a reliable and high-quality global chemical material supplier and manufacturer. It has more than 12 years of experience providing ultra-high quality chemicals and nanotechnology materials, including silicon nitride, nitride powder, graphite powder, sulfide powder, and 3D printing powder. If you are looking for high-quality and cost-effective silicon nitride, you are welcome to contact us or inquire at any time.
Amorphous Boron Powder | High Purity Graphite Powder | Boride Powder | 3D Printing Powder | Zinc Sulfide ZnS Powder | Oxide Powder | Silicide Powder