Preparation and application scope of silicon nitride ceramics

Silicon nitride ceramic is an inorganic material ceramic that does not shrink during the sintering process. Silicon nitride is very strong, especially hot-pressed silicon nitride, which is one of the hardest materials in the world. It has high strength, low density, high temperature resistance and other properties.

Preparation of silicon nitride ceramics

The preparation process of Si3N4 ceramics is mainly concentrated in the reaction sintering method, hot pressing sintering method, atmospheric sintering method, air pressure sintering method and other types.

Reaction sintering method (RS)

Use general molding method. First, the silicon powder is pressed into a green body of the desired shape and placed in a nitriding furnace for pre-nitriding (partial nitriding) sintering. The pre-nitrided body already has a certain strength. Various mechanical processing (such as turning, planing, milling, drilling) can be carried out. Finally, the temperature is higher than the melting point of silicon; the green body is completely nitrided and sintered again, resulting in a product with little dimensional change.

Hot Press Sintering (HPS)

It uses Si3N4 powder and a small amount of additives (such as MgO, Al2O3, MgF2, Fe2O3, etc.) for hot pressing and sintering at a pressure above 1916MPa and a temperature above 1600°C. The mechanical properties of Si3N4 ceramic produced by hot pressing sintering method are better than reaction sintered Si3N4, and it has higher strength and density.

Atmospheric pressure sintering (PLS)

In increasing the pressure of the sintering nitrogen atmosphere, it uses the characteristics of Si3N4 to increase the decomposition temperature (usually N2=1atm, starting from 1800°C). After the atmospheric pressure sintering is carried out in the temperature range of 1700-1800°C, the air pressure sintering is carried out in the temperature range of 1800-2000°C.

 Pneumatic sintering method (GPS)

The gas pressure sintering of silicon nitride is carried out at a pressure of 1-10 MPa and a temperature of about 2000°C. The high nitrogen pressure inhibits the high temperature decomposition of silicon nitride. Due to the use of high temperature sintering, there are few sintering aids, which are sufficient to promote the growth of Si3N4 grains, and obtain long columnar grains and high toughness ceramics with in-situ growth density >99%.

Silicon nitride ceramic application

Silicon nitride ceramics have excellent mechanical properties, wear resistance, corrosion resistance and other excellent properties, making them widely used in metallurgy, machinery, energy: semiconductors, chemicals, aerospace and many other industrial fields.

Overview of silicon nitride Si3N4 powder

Silicon nitride Si3N4 powder is an inorganic substance with a chemical formula of Si3N4. It is an important structural ceramic material with high hardness, inherent lubricity, wear resistance, atomic crystal, and high temperature oxidation resistance.

Application of silicon nitride Si3N4 powder

The main uses of silicon nitride Si3N4 powder are as follows

1) Manufacturing structural equipment: metallurgy, machinery, aviation, aerospace, etc.

2) Surface treatment of metals and other materials: such as molds, knives, turbine blades.

3) Composite materials: such as metal, ceramic and graphite composite materials, rubber, and plastics.

4) Colorless, transparent, self-lubricating and wear-resistant nano-particle film, used for high-level surface protection such as mobile phones and automobiles.

5) Ball bearings.

6) Ball valves and parts.

7) Corrosion resistant turbine.

Other applications of silicon nitride Si3N4 powder

Silicon nitride Si3N4 powder is used as high-grade refractory material. For example, SI3N4-SIC refractories and sic are used in blast furnace bodies and other parts, and SI3N4-BN materials and BN are used in horizontal continuous casting separation rings. Continuous casting separation ring is a fine structure ceramic material with uniform structure, high mechanical strength, good thermal shock resistance, and will not be wetted by molten steel, which meets the requirements of continuous casting process

Silicon nitride Si3N4 powder ceramic material has excellent properties such as high thermal stability, strong oxidation resistance, and high product dimensional accuracy. Since silicon nitride is a covalent compound with high bonding strength, it can form an oxide protective film in the air, so it also has good chemical stability and will not be oxidized below 1200°C. The protective film formed at 1200~1600°C can prevent further oxidation and will not be penetrated by many molten metals or alloys such as aluminum, lead, tin, silver, brass, and nickel. Or corrosion, but it can be corroded by molten magnesium, nickel-chromium alloys, stainless steel and other melts.

Silicon nitride Si3N4 powder ceramic materials can be used for high-temperature engineering parts, advanced refractories in the metallurgical industry, corrosion-resistant parts and seals in the chemical industry, tools and knives in the machining industry, etc. It can form a strong bond with silicon carbide, aluminum oxide, thorium dioxide, boron nitride, etc., so it can be used as a bonding material to be modified in different proportions.

In addition, silicon nitride can also be applied to solar cells. After the silicon nitride film is coated by the PECVD method, it can not only be used as an anti-reflection film to reduce the reflection of incident light, but also in the deposition process of the silicon nitride film, the hydrogen atoms of the reaction product enter the silicon nitride film and the silicon wafer passivation Defects. The ratio of the number of silicon nitride to silicon atoms here is not strictly 4:3, but depends on the process conditions within a certain range. Internal fluctuations, different atomic ratios correspond to different physical properties of the film.

Used in ultra-high temperature gas turbines, aircraft engines, electric furnaces, etc.

Silicon nitride Si3N4 powder price

The price of silicon nitride Si3N4 powder will change randomly according to factors such as production cost, transportation cost, international situation, exchange rate, and supply and demand of silicon nitride Si3N4 powder market. Tanki New Materials Co., Ltd. aims to help various industries and chemical wholesalers find high-quality, low-cost nanomaterials and chemicals by providing a full set of customized services. If you are looking for silicon nitride Si3N4 powder, please feel free to send an inquiry to get the latest price of silicon nitride Si3N4 powder.

Silicon Nitride Si3N4 Powder Supplier

As a global silicon nitride Si3N4 powder supplier, Tanki New Materials Co., Ltd. has extensive experience in the performance, application and cost-effective manufacturing of advanced engineering materials. The company has successfully developed a series of powder materials (titanium nitride, silicon nitride, titanium nitride, etc.) high-purity targets, functional ceramics and structural devices, and provides OEM services.

Specification of Silicon Nitride Si3N4 Powder:
Product Name:Silicon Nitride
Purity:99%
Particle Size:0.5um-1um (α phase)

Chemical Composition of Silicon Nitride Si3N4 Powder: