White corundum thermodynamic properties
White corundum is a high-temperature and corrosion-resistant material. It is not only used in the grinding field, but also widely used in refractories, ceramic products and other industries. Its main component is electrofused aluminum oxide, which is named after its molten production process. White corundum has good thermodynamic properties and can be used in abrasive tools, ceramics, coatings, wear-resistant and other fields.
The melting point of white corundum abrasive shall not be lower than 2050 ° C, the refractoriness of refractory products produced shall be greater than 1900 ° C, the starting temperature of load softening shall be about 1850 ° C, the limit service temperature shall be 1950 ° C, and the long-term service temperature shall be 1800 ° C. However, the thermal expansion coefficient of white corundum is 8.6, which belongs to the refractory material with medium thermal shock resistance. It is usually mixed with sintered corundum or other materials to make corundum refractory products. Nevertheless, the thermodynamic properties of white corundum abrasives can completely meet the temperature required for molding and curing of bonded abrasives, such as Vitrified abrasives and resin-bonded abrasives. The Mohs hardness of white corundum is 9. It is lower than that of diamond, silicon carbide and a few synthetic hard minerals. The products made of white corundum have high strength, and the compressive strength at room temperature can reach 2000MPa; The bending strength at normal temperature can reach more than 250 MPa, and the bending strength at 1000 ℃ is 150 MPa. High-density alumina products can better resist the erosion of molten metals such as iron, aluminum, nickel, vanadium, etc; At normal temperatures, it will not be corroded by sulfuric acid, hydrochloric acid, nitric acid and hydrofluoric acid, but at high temperatures, sodium fluoride and concentrated sulfuric acid will corrode alumina to a certain extent. White corundum abrasive has certain resistance to the erosion of glass and slag. The abrasive products made of it will not react with the grinding workpiece in the high-temperature environment caused by grinding. Therefore, it will not damage the surface of the workpiece.
