Currently, ceramic materials are increasingly used in ferrous and non-ferrous metallurgy, glass and refractory industries. They have unique properties that can improve various areas of production. The most promising ceramic material is silicon nitride. This is the substance of the future, thanks to which various technological industries are being rebuilt. For example, such as the gold mining industry and all kinds of processing plants.
What is this substance?
Silicon nitride is a unique ceramic material that is used in many industries. It belongs to the group of non-oxide ceramics, as it does not contain oxygen atoms.
Formula of silicon nitride: Si 3 N 4 .
Structure
The microstructure of Si 3 N 4 is a micro rod, which form a cylindrical crystal. This property turned out to be fundamentally important when processing various types of cast iron, in particular the one that contains ceramic inserts. When using various metals as cutting materials, the speed is not as high as required, so it is necessary to use a variety of cutting lubricants. Due to the amazing structure of silicon nitride, its use for cutting iron makes it possible to achieve maximum speed without the need for lubricating fluids. Due to its unique composition, this material has a high toughness, which means that the substance has a high resistance to shock.
Getting
There are various methods for preparing this compound. One of them is chemical deposition, which is carried out at temperatures from 700 to 900 ° C. Using this method, the compound is obtained in an amorphous form, which is a dielectric. In this case, the possible content of hydrogen in this material can be up to 8%. In this case, the nitrogen and silicon atoms can form hydrogen bonds with the hydrogen contained in the amorphous precipitate. There is a dependence of the content of hydrogen atoms on the temperature at which the deposition was carried out, as well as on the ratio of the starting materials in the gas mixture.
The highest content of a substance appears if silicon nitride is deposited at low temperatures and at a high concentration of ammonia in a gaseous mixture. If the process is carried out in a small ratio of ammonia to dichlorosilane, the material will include a sufficiently large amount of silicon, which leads to the formation of insufficient dielectric properties. Resistance with respect to electricity Si 3 N 4 also depends on the temperature conditions under which it is obtained.
Obtaining silicon nitride is a complex process, where it is necessary to take into account a variety of conditions, so that the product meets the requirements. Given the important areas in which it finds its application, it is necessary to responsibly approach the conditions for the deposition.
Silicon Nitride Properties
This material is a substance with unique physical and physico-chemical properties.
One of the most important features is that this substance has a low density and the highest toughness, which leads to the possibility of using silicon nitride materials as balls for light bearings.
This material is heat resistant. It can be used at 1300 ° C in an oxidizing atmosphere and at 1600 ° C in a neutral one. These properties are also important for use in various kinds of industrial production, for example, during welding processes.
Application
Due to its unique characteristics, silicon nitride is widely used in various areas of the processing industry. This material is of the greatest importance for the iron industry, since using it as cutting devices, you can increase the speed of the process, as well as abandon the use of coolers and lubricants.
In addition, due to its high heat resistance under various atmospheres, Si 3 N 4 is used in welding various materials. Due to the unique combination of tribological properties, balls for various types of bearings are made of silicon nitride.