Precautions for green silicon carbide, silicon carbide requirements for time

The use of grinding wheels is dangerous. For everyone's safety, the following is a list of precautions in use: grinder is one of the most commonly used machinery and equipment in machinery factories, whether its installation is reasonable and whether it meets safety requirements; Whether it is used correctly and whether it complies with safety operating procedures.

These problems are directly related to the personal safety of every employee, so we must pay enough attention to it in actual use.

1. It is used for wire cutting of 3-12 inch monocrystalline silicon, polycrystalline silicon, potassium arsenide and quartz crystals. It is an engineering processing material for the solar photovoltaic industry, semiconductor industry, and piezoelectric crystal industry.

2. The content of silicon in silicon carbide determines the hardness of silicon carbide. The particle size of silicon carbide has a great influence on wire cutting, but the most important thing is the particle shape of silicon carbide.

3. Detection method: the content of silicon needs to be detected by atomic absorption (high detection efficiency and accurate value).

4. The size of silica particles requires a resistance particle analyzer (high efficiency).

5. Silicon carbide particle type detection requires Rise RA200 particle analyzer. (The particle shape coefficient can be analyzed for roundness more accurately).

Green silicon carbide is made of petroleum coke and high-quality silica as the main raw material, adding salt as an additive, smelting at high temperature through a resistance furnace, and the crystalline body smelted by smelting has high purity and high hardness, its hardness is between corundum and diamond, and its mechanical strength is higher than that of corundum. Green silicon carbide powder is green, crystal structure, high hardness, strong cutting ability, stable chemical properties, and good thermal conductivity.

Green silicon carbide is a type of silicon carbide abrasive commonly used in the abrasive industry. Its performance is stable, the structure is unique, and the application range is very wide, not only in the field of abrasive industry, but also in other industrial fields have many applications.

So how is green silicon carbide used in all walks of life? Today I will give you a specific summary.

1. It is used in metallurgical ore processing. Green silicon carbide has strong wear resistance, second only to diamond in hardness, and is an ideal material.

2. It is used in the building materials ceramic grinding wheel industry. Take advantage of its characteristics, thermal conductivity, thermal radiation and high temperature strength to make a plate kiln. It not only reduces kiln capacity, but also improves furnace capacity and product quality and shortens production cycles.

It is also ideal for indirect material sintered ceramic glazed baking.

3. Application of energy saving. Taking advantage of its good thermal conductivity and thermal stability, the heat exchanger saves 20% of fuel consumption and 35% of fuel and increases productivity by 20-30%.

4. It is used in the non-ferrous metal smelting industry. Heat the material indirectly with green silicon carbide at high temperature, strength, good thermal conductivity and impact resistance, high temperature.

5. It is used in the steel industry. Large-scale blast furnace with green silicon carbide corrosion resistance, thermal shock wear resistance and good thermal conductivity to improve service life.

With the rapid development of the photovoltaic industry, the industry's demand for silicon wafers is heating up day by day, and the demand for green silicon carbide powder, as an important auxiliary material for the production of crystalline silicon wafers, is naturally increasing. At present, green silicon carbide powder is mainly used in China, because its own characteristics determine that it is more suitable for the cutting of photovoltaic and semiconductor crystalline silicon wafers.

Green silicon carbide is used in casting, the effect is relatively good, especially in smelting, increasing the graphite core, increasing the number of graphite balls of ductile iron, improving the graphite form of gray iron, etc.

The use of green silicon carbide is more widely used in foreign countries, whether it is an electric furnace or a cupola, this substance is added. Because the melting point of green silicon carbide is very high, about 2700 degrees, then in our ordinary casting production furnace, it is impossible to have such a high temperature, in our casting and smelting temperature, the dissolution of green silicon carbide is gradually decomposed in the molten state, diffusion, relatively slow, so the time to add green silicon carbide in the furnace should be earlier than other alloys, generally added when the charge is smelted to one-third to one-half of the furnace, so that it has sufficient temperature and time conditions to decompose.

At present, a large number of cupboards have been eliminated in China, and the use of induction furnaces, carburizers, and green silicon carbide experience is particularly important.

Take green silicon carbide as an example with a content of 90%, the amount added, and the ingredients are as follows: the total weight of the ingredients is 1600 kg, 800 kg of the cupola furnace poured from the furnace (in the past, when the power frequency furnace began to send electricity, it was convenient to increase the power of the round large iron block), 800 kg of scrap steel, 40 kg of green silicon carbide, added in batches, and finally added recarburizer. The ingots are carbon, silicon, manganese, phosphorus, and sulfur.

The final smelting composition of the electric furnace, since it is an experiment, the carbon content is divided into several grades, from, silicon in the left and right.

The conclusion is that after the addition of green silicon carbide, the graphite form becomes thicker and shorter, the spacing is larger, the number of eutectic groups is increased, the relative strength and relative hardness of cast iron are improved, and the supercooling degree of molten iron after inculation is reduced.

Silicon carbide has a time requirement, and the decomposed silicon is combined with the carbon in the charge to become a new silicon carbide. In the early stage of furnace power transmission, the main part of the electric heat is used to heat the charge, and the heat used to form silicon carbide is only a small part. In the middle of power transmission, the amount of hot socks used to form silicon carbide accounts for a large proportion.

In the later stages of power transmission, heat loss accounts for the main part. Adjust the relationship between power transmission power and time, and optimize the favorable power outage time, in order to obtain a good electric heat utilization rate. The high-power resistance furnace usually chooses to have a power transmission time of about 24 hours, so as to arrange the operation of Napai Soli.

On this basis, the relationship between the power of the electric furnace and the specifications of the furnace is adjusted.

The manufacturing method of green silicon carbide is the same as that of black silicon carbide, but the purity of the raw materials used is higher, and it is also formed at a high temperature of about 2200 °C in the resistance furnace, green, translucent, hexagonal crystal shape, its SiC content is higher than that of black, and the physical properties are similar to black silicon carbide, but the performance is slightly brittle compared with black, and it also has good thermal conductivity and semiconductor characteristics.

Industrial green silicon carbide varies with its purity due to the different types and contents of impurities it contains. The crystal structure is divided into -sic of hexagonal or rhombohedral and -sic of cube.

More than 70 varieties of SiC have been found due to the different stacking sequences of carbon and silicon atoms in their crystal structures. -SiC is converted to -SiC, green silicon carbide above 2100.

The industrial manufacturing method is to use high-quality quartz sand and petroleum coke to refine in a resistance furnace. The green silicon carbide blocks obtained are crushed, acid-alkali washing, magnetic separation and screening or water separation to make products of various particle sizes.

Specific uses of green silicon carbide:

1. As an abrasive, it can be used to make abrasives, such as grinding wheels, oil stones, grinding heads, sand tiles, etc.

2. As a metallurgical deoxidizer and high-temperature resistant material.

3. High-purity single crystal, which can be used to manufacture semiconductors and silicon carbide fibers.

4. It is mainly used in crystal grinding, monocrystalline silicon wire cutting, ceramic polishing, as well as the manufacture of precision grinding wheels, filling and modification of plastic products, and many other fields.

5. It can be used for crystal cutting and precision grinding, precision grinding of hard glass, slicing of monocrystalline silicon and polycrystalline silicon rods, precision grinding of monocrystalline silicon wafers, processing of superhard metals, processing of soft metals such as copper and copper alloys, processing of various resin materials, etc.

6. It is an ideal material for super-fine grinding oil stone. It has very good thermal conductivity and high temperature resistance.