Are there any shortcomings in the production and application of silicon nitride ceramics?

Are there any shortcomings in the production and application of silicon nitride ceramics?

Although silicon nitride has good properties, it also has the common characteristic of ceramics—brittleness. Silicon nitride ceramic is a polycrystalline sintered body composed of crystal grains bonded by ions or covalent bonds. Highly oriented chemical bonds determine the low density of grain dislocations, less slip systems and low crack growth energy in ceramics. 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 reliability in applications. Therefore, improving its toughness and improving its reliability has always been an important research direction of silicon nitride ceramics.

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 effects of cold and heat. If it is heated to above 1000°C in the air, cooled quickly, and then heated quickly, it will not break. It is precisely because of the excellent characteristics of silicon nitride ceramics that people often use it to manufacture mechanical parts such as bearings, turbine blades, mechanical seal rings, permanent molds, and so on. If the heating surface of the engine parts is made of high temperature resistant and difficult heat transfer silicon nitride ceramics, it will not only improve the quality of the engine, but also save fuel.

Overview of silicon nitride

Silicon nitride 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 crystals,and oxidation resistance at high temperatures.

Application of silicon nitride

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

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

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

4)Colorless and transparent self-lubricating wear-resistant nanoparticle film,used for advanced surface protection such as mobile phones and automobiles.

5)Ball bearings.

6)Ball valve and parts.

7)Corrosion resistant turbine.

Other applications of silicon nitride

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

Silicon nitride ceramic materials have excellent properties such as high thermal stability,strong oxidation resistance and high product size accuracy.Since silicon nitride is a covalent compound with high bond strength,and can form an oxide protective film in the air,it is also It has good chemical stability.It will not be oxidized below 1200℃.The protective film formed at 1200~1600℃ can prevent further oxidation and will not be infiltrated 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 alloy,stainless steel and other melts.

Silicon nitride ceramic materials can be used for high-temperature engineering parts,advanced refractories in the metallurgical industry,corrosion-resistant parts and sealing parts in the chemical industry, tools and cutting tools in the machining industry,etc.Because of silicon nitride and silicon carbide,alumina ,Thorium dioxide, boron nitride,etc.can form a strong bond,so it can be used as a bonding material and modified in different proportions.

In addition,silicon nitride can also be applied to solar cells.After the silicon nitride film is plated 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 reaction The hydrogen atoms of the product enter the silicon nitride film and the silicon wafer to passivate defects.The ratio of the number of silicon nitride to silicon atoms here is not strictly 4:3,but is in a certain range depending on the process conditions.Internal fluctuation,the physical properties of the film corresponding to different atomic ratios are different.

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

The price of silicon nitride

The price of silicon nitride will vary randomly with the production cost, transportation cost, international situation, exchange rate and supply and demand of silicon nitride 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, please feel free to send an inquiry to get the latest price of silicon nitride.

Suppliers of silicon nitride

As a global silicon nitride 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.