Copper is industrial pure copper with a melting point of 1083°C, no allotropic transformation, and a relative density of 8.9g/cm3, which is five times that of magnesium. The mass of the same volume is about 15% heavier than ordinary steel. Because of its rose red color and purple color after the oxide film is formed on the surface, it is generally called red copper. It is copper containing a certain amount of oxygen, so it is also called oxygen-containing copper. The impurities in it are oxidized and discharged, and the amount of solid solution is reduced, which is beneficial to the electrical conductivity of copper and can also eliminate the influence of harmful impurities. However, copper is prone to embrittlement (known as hydrogen disease) in reducing atmospheres above 370°C. There are three grades of copper in my country: T1, T2, and T3, of which T2 copper is widely used. T1, T2, T3 copper is divided according to the different chemical composition. The copper content of T1 red copper is more than 99.95%, and the sum of impurities does not exceed 0.05%; the copper content of T2 red copper is more than 99.90%, and the total impurity content does not exceed 0.1%; the copper content of T3 red copper is more than 99.7%, and the total impurity content does not exceed 0.3%. .
Copper has excellent electrical conductivity, thermal conductivity, good corrosion resistance and processing performance, and can be welded and brazed. T1 and T2 copper are mainly used as conductive, thermally conductive, and corrosion-resistant components, such as wires, cables, conductive screws, shells, and various conduits, including the aviation industry. T3 copper is mainly used as a structural material, such as making electrical switches, washers, rivets, nozzles and various conduits; it is also commonly used in some less important conductive