Reaction sintering silicon carbide is an important method to produce high performance ceramic materials. This method uses heat treatment of carbon and silicon sources at high temperatures to make them react to form silicon carbide ceramics.
1. Preparation of raw materials. The raw materials of reaction-sintered silicon carbide include carbon source and silicon source. The carbon source is typically carbon black or a carbon-containing polymer, while the silicon source is powdered silica. These raw materials need to be crushed, screened and mixed to ensure uniform particle size, while also controlling their chemical composition in order to obtain high-quality silicon carbide ceramics during heat treatment.
2. Shape. Put the mixed raw materials into the molding mold for molding. There are many kinds of molding methods, commonly used are press molding and injection molding. Press molding is the compression of raw material powder under pressure to form, while injection molding is the raw material mixed with an adhesive, it is sprayed into the mold through a syringe to form. After forming, it is necessary to carry out demoulding treatment to remove the ceramic billet from the mold.
3. Heat treatment. The formed ceramic body is put into the heat treatment furnace for sintering. The sintering process is divided into two stages: carbonization stage and sintering stage. In the carbonization stage, the ceramic body is heated to a high temperature (usually above 1600 ° C) under an inert atmosphere, and the carbon source reacts with the silicon source to produce silicon carbide. In the sintering stage, the temperature is raised to a higher temperature (usually above 1900 ° C), which causes recrystallization and densification between silicon carbide particles. In this way, the density of the silicon carbide body is further improved, while the hardness and wear resistance are also significantly improved.
4. Finishing. The sintered ceramic body needs to be finished to obtain the desired shape and size. Finishing methods include grinding, cutting, drilling, etc. Due to the extremely high hardness of silicon carbide material, it is difficult to finish, requiring the use of high-precision grinding tools and processing equipment.
In summary, the production process of reaction-sintered silicon carbide includes the preparation of raw materials, molding, heat treatment and finishing. Among them, the key step is the heat treatment process, the control of which is crucial to obtain high-quality silicon carbide materials. It is necessary to control the temperature, atmosphere, holding time and other factors of the heat treatment to ensure that the reaction is sufficient, the crystallization is complete and the density is high.
The advantage of the reaction-sintered silicon carbide production process is that ceramic materials with high hardness, high strength, high wear resistance and high temperature stability can be prepared. This material not only has excellent mechanical properties, but also has excellent corrosion resistance and high temperature properties. Silicon carbide materials can be used to manufacture various engineering parts, mechanical seals, heat treatment devices, furnace ceramics and so on. At the same time, silicon carbide materials can also be used in semiconductor, solar energy, magnetic materials and other fields.
In short, reaction sintering silicon carbide is an important method to prepare high performance ceramic materials. The production process requires fine control of each link to obtain high-quality silicon carbide materials. Reaction-sintered silicon carbide materials have excellent mechanical properties, corrosion resistance and high temperature properties, and have wide application prospects in various industrial and scientific fields.
Post time: Jul-21-2023