1. Brown fused alumina:
The main chemical component is AL2O3, which is made by smelting bauxite, iron filings and anthracite in an electric arc furnace. The color of brown corundum abrasive is brown, and in terms of its color, it is named brown corundum. This kind of abrasive has a certain degree of hardness and toughness, has a strong grinding ability, and can withstand great pressure. It has the characteristics of high temperature resistance, oxidation resistance, corrosion resistance and good chemical stability. Because of its high tensile strength, it is suitable for grinding materials with high tensile strength. It is suitable for ordinary steel, high carbon steel, alloy steel, and can be used for the processing of hard wood. It can also be used as a substitute when other abrasives are insufficient. Abrasive is the most widely used abrasive.
2, white corundum:
The main chemical composition is AL3O2, which is made by smelting aluminum oxide powder in an electric arc furnace. The color is white, and it is named white corundum in terms of its color. The texture of white corundum is purer than brown corundum. The raw material of alumina powder is processed in advance from bauxite used in brown corundum. The main physical component is β-AL2O3 (without grinding ability), which is converted from β-AL2O3 to α-AL2O3 by electric arc furnace smelting. The converted α-AL2O3 has a strong grinding force.
3, black silicon carbide:
The main chemical component is SiC. It is made by smelting petroleum coke, quartz sand, sawdust, etc. in a resistance furnace. The color of black silicon carbide is black, and in terms of its color, it is named black silicon carbide. The texture of black silicon carbide is brittle and harder than corundum abrasives, and its toughness is also inferior to corundum abrasives. For materials with lower tensile strength, such as non-metallic materials (various plates such as wood plywood, particle board, high, medium and low density fiberboard , Bamboo board, calcium silicate board, leather, glass, ceramics, stone, etc.) and non-ferrous metals (aluminum, copper, lead, etc.) and other materials are particularly suitable for processing. It is also an ideal abrasive for processing hard and brittle materials. .
4. Green silicon carbide:
The main chemical component is SiC. The raw materials used in the manufacturing are roughly the same as those used in the production of black silicon carbide. In addition, industrial salt is added as a reactant and accelerator to react in a resistance furnace. In terms of its color, it is green, so it is named green silicon carbide. Green silicon carbide is purer in texture than black silicon carbide, and its hardness is higher than black silicon carbide. Its grinding uses are the same as black silicon carbide. It is more suitable for fine grinding of materials such as thread grinding, grinding tools, etc. Grinding materials are more widely used for workpieces of cemented carbide and diamond products. Since the production cost of green silicon carbide is higher than that of black silicon carbide, the price of green silicon carbide products is higher than that of black silicon carbide. Black silicon carbide is higher. Therefore, the selection of green silicon carbide is compared with black silicon carbide. In terms of non-metallic and non-ferrous metal materials, green silicon carbide is generally not used, and green silicon carbide is mainly used for the grinding of cemented carbide and precision grinding. Even fewer choose green silicon carbide as the grinding material on abrasive belts and other coated abrasive tools.
5, microcrystalline corundum:
The main chemical composition is AL2O3, and the production raw materials used are the same as brown corundum, but the rapid cooling process is used in the smelting process to obtain the effect of fine crystallization. The finely crystalline corundum has higher mechanical strength than ordinary corundum. Abrasive tools made of microcrystalline corundum are often used for rough grinding of difficult-to-grind materials such as cast steel and high-toughness titanium-nickel alloy steel, but they are rarely used to make coated abrasive tools.
6, chrome corundum:
is to add a mixture of Cr2O3 in the production process of white corundum, so that this corundum forms a eutectic of white corundum and Cr2O3, which changes the properties and structure of the corundum. The toughness of chromium corundum is higher than that of white corundum, and its hardness is about the same as that of white corundum. The amount of Cr2O3 added is slightly different from the performance of the produced chromium corundum, and its color is also different. In chromium corundum, because of the different content of Cr2O3, its use is different. Therefore, it is also used in abrasives such as chromium corundum. The division is divided into several grades according to the different addition of Cr2O3. The chromium corundum grinding material is often used for the sharpening of hardened steel, alloy steel and rebar and the precision grinding of instrument and meter parts. Chromium corundum is often used in the production of fixed abrasive tools, but is rarely used in the manufacture of coated abrasive tools.
7, hollow ball abrasive:
The so-called hollow ball abrasive refers to a collection of spherical abrasives formed by uniformly coating the abrasive on the surface of a hollow ball made of plastic with a diameter of 0.05-1mm, and then the hollow ball abrasive is made according to the general convention Method: The abrasive belt is made after coating on the surface of the substrate.
hollow ball abrasives are generally used in the production of fine-grained products. Because the abrasive is very fine, if it is directly coated on the surface of the substrate, the abrasive layer is very thin, there are fewer abrasives involved in the grinding, the grinding efficiency is poor, and the abrasive is very fine, and the surface porosity of the abrasive belt is very low. Sometimes it is easy to block. If hollow ball abrasives are used, the surface of the abrasive belt will form a very "rough" grinding surface, and the surface pores will be greatly increased. The surface of the abrasive belt will help eliminate the blockage of grinding, and more importantly, the surface of the abrasive belt will participate in the grinding. The number of abrasive particles will increase several times or tens of times, and the increase number is determined by the ratio of the ball diameter to the particle size. The larger the ratio, the larger the added abrasive particles, thus greatly improving the grinding efficiency and durability. Abrasive belts such as hollow ball abrasives are patented by the German company HERMES. For the company, this type of product is specifically called "HERMESIT".
8. New ceramic abrasive with microcrystalline structure:
It is a sintered ceramic abrasive manufactured by the gel method. Its crystal size is about 1-3 microns. It is hard and tough. During grinding, the tiny crystals gradually fall off to expose new crystals, keeping the entire abrasive grain sharp. In 1981, the US 3M Company Put into the market in the year, the abrasive belt made from it named Cubutron, the grinding hammer head is 71% higher than the cutting efficiency of the zirconium corundum belt, and the efficiency of grinding the nickel stainless steel is 150% higher than that of the zirconium corundum belt. There are also SG abrasives from NORTON in the United States. The amount of metal to be ground is 5 times higher than brown corundum with SG abrasive belts at 400 PSI pressure (abrasive belt speed is 28 m/s); CB ceramic abrasive belts named by German Hermes Abrasive belts, coated abrasives made of this type of abrasive are particularly suitable for processing difficult-to-grind materials under high-strength pressure, such as aerospace alloys, high-nickel alloy steels, vanadium-containing tool steels, and cobalt-containing alloy steels.
In addition, recently foreign industrialized countries have also developed coated abrasives made of synthetic diamond and cubic boron nitride (CNB) abrasives, which specialize in processing cemented carbide, quartz components and difficult-to-machine steels.
9, zirconium corundum abrasive:
is a high toughness abrasive with ZrO2 added and crystal size of 20 microns. There are two kinds of ZrO2, 40% and 25%, which are used to coat abrasive tools, which should have sharper shaped abrasive grains, which are especially suitable for processing stainless steel parts and titanium alloy parts. In the Chinese market, zirconium corundum belts from NCA in Japan, NORZON belts from NORTON in the United States and YZ533 and YZ633 zirconium corundum belts from South Korea’s Koryo Grinding Company are more popular. According to the information provided by the American NOTON company, its grinding efficiency is 254-300% higher than that of brown corundum. Using NORZON abrasive belt to process particle board, the life of the abrasive belt is increased by 3 times.
But the zirconium corundum abrasive belt is not only used as an abrasive belt, but also in a large number of fixed abrasive tools.
10, compound abrasive:
refers to the mechanical compound of one kind of abrasive with another kind of abrasive instead of the compound of chemical reaction. In the manufacture of abrasive tools, the two kinds of abrasives are mechanically added to the molding material, and the various abrasives still maintain their unique physical and chemical properties. When using it, take each of its strengths to play its own advantages, and achieve the purpose of better results. In order to achieve the purpose of grinding, composite abrasives are often used abroad or at home to produce abrasive tools for difficult-to-process materials. This is the so-called method of creating a name and another brand. Common composite abrasives include the compound of brown corundum and white corundum, the combination of corundum and green silicon carbide, the combination of brown corundum and black silicon carbide, and so on.
Composite abrasives are commonly used in fixed abrasive tools, and are rarely used in the manufacture of coated abrasive tools.
