Production method of reaction-sintered silicon carbide

　　Reaction-sintered silicon carbide is a new type of high-tech ceramic material characterized by high strength, high hardness, excellent wear resistance, and superior corrosion resistance. It is widely used in fields such as metallurgy, petrochemicals, electronics, and aerospace. This product is made by using silicon carbide abrasives along with carbon black, graphite, and various additives, and is processed into a porous structure via methods such as dry pressing, extrusion, or casting. Now, let’s explore this further together. Reaction-sintered silicon carbide The production method, right!

　　Reaction-sintered silicon carbide—this invention represents years of research by the inventor into raw material formulations and manufacturing processes, particularly a unique continuous sintering process. After thousands of experiments, it has evolved into a relatively mature technical solution.

　　 Reaction-sintered silicon carbide In claim 1 of the present invention, the weight proportions are as follows: silicon carbide fine powder—5 to 8 parts; carbon black—0.5 to 1.5 parts; graphite—1 to 1.5 parts; and binder—0.1 to 0.5 parts. Among these, the particle size distribution of silicon carbide is as follows: 3 to 5 parts of SiC with a particle size of (90–30 μm); and 2 to 3 parts of SiC with a particle size of (30–0.8 μm). The methyl cellulose and polyvinyl alcohol powders from the gazelle are each separately added to an appropriate amount of water—0.1 to 0.5 parts—and after heating, a transparent solution is obtained.

　　1. Mix the various powders, binders, and solutions prepared according to the formulation, and stir thoroughly until uniform.

　　2. Clean the casting mold and evacuate it to a vacuum level of 0.1 MPa, then inject the prepared mixed slurry under pressure. After a specified period of time, release the slurry and remove the green body. Allow it to dry at a temperature of 30–70°C for 18–20 hours.

　　3. Trim the steel billet according to the requirements specified in the drawing.

　　4. Place the reaction-sintered blank into the furnace, add 1 to 3 parts by weight of metallic silicon, and perform vacuum sintering. The process is divided into three temperature stages: low temperature (0–700°C), held for 3–5 hours; medium temperature (700–1400°C), held for 4–6 hours; and high temperature (1400–2200°C), held for 5–7 hours. Once the temperature drops below 150°C, stop the furnace and open it.

　　5. Use sandblasting to remove silicon residue from the surface of the polished product; employ sandblasting for grinding.

　　6. Place the oxidized products into the oxidation furnace, heat up to 1350°C over 24 hours, and allow them to cool naturally. After removal and passing inspection, store them in the warehouse.

　　The raw materials and proportions used in the method of this invention are scientifically sound and reasonably selected, ensuring that the green body has sufficient porosity and good density. Moreover, the optimized sintering heating rate, temperature, and holding time guarantee high flexural strength of the final product. The key performance and quality characteristics achieved by this method have reached internationally advanced levels. The main technical indicators are as follows:

　　Specific Implementation Methods for Reaction-Sintered Silicon Carbide

　　Example 1 Reaction-sintered silicon carbide Manufacturing method of the bundle:

　　1. Take 0.3 parts by weight of adhesive as the raw material, add a certain amount of water, and mix thoroughly. The ingredients include 6.8 parts by weight in total: 3.8 parts of silicon carbide fine powder with a particle size of 90–30 μm, 3 parts of silicon carbide fine powder with a particle size of 30–0.8 μm, 1 part of carbon black, and black...

　　2. During casting, first clean the mold to be used, align it properly, and secure it with fasteners. Then, use a pressure device to draw the slurry out of the container and inject nitrogen gas into the container at a pressure of 0.1 MPa to perform pressure casting, forcing the slurry into the mold. After waiting for one hour, release the slurry; six hours later, remove the mold, take out the blank, and place it in a drying chamber for drying. Remove it within 30–70 hours, or 18–20 hours. 3. When repairing the blank, first check whether the blank meets the design requirements. If it does, proceed to repair the blank according to the drawings. After passing inspection, send it to the high-temperature drying chamber.

　　4. After the moisture content of the reaction-sintered green body reaches 1%, remove it and clean the green body by blowing air, then weigh it. Add 2.9 parts by weight of metallic silicon. Nitrogen gas can be introduced to create a vacuum for sintering. The sintering process consists of: low temperature at 700°C for 4 hours; medium temperature at 1400°C for 5 hours; and high temperature at 2200°C for 6 hours. After the temperature has been reduced over a period of 12 hours and reached 150°C, stop the furnace operation and open the furnace.

　　5. After the sandblasted product is finished, grind off the silicon residue on its surface using sandblasting.

　　6. The purpose of the oxidation treatment is to remove the oxides formed during the sintering process. The product is placed in an oxidation furnace, where it is heated to 1350°C over a period of 24 hours, and then allowed to cool naturally. After removal from the furnace, the product is inspected before being stored.

　　The raw materials and proportions used in the method of this invention are scientifically sound and reasonably selected, ensuring that the green body has sufficient porosity and good density. Moreover, the optimized sintering heating rate, temperature, and holding time guarantee high flexural strength of the final product. The key performance characteristics and quality of products manufactured by this method have reached internationally advanced levels.

　　The above is an introduction to the production method of reaction-sintered silicon carbide. If you’d like to learn more, feel free to contact us anytime!