Copper and copper alloys& nbsp; 1、 Pure copper is a rose red metal with a purple color after the formation of an oxide film on the surface. Therefore, industrial pure copper is often referred to as purple copper or electrolytic copper. Density 8-9g/cm3, melting point 1083° C. Pure copper has good conductivity and is widely used in the manufacturing of wires, cables, brushes, etc; Good thermal conductivity, commonly used to manufacture magnetic instruments and meters that require protection against magnetic interference, such as compasses and aviation instruments; Excellent plasticity, easy to hot press and cold press processing, can be made into copper materials such as pipes, bars, wires, strips, plates, foils, etc. There are two types of pure copper products: smelted products and processed products. See Tables 6 and 7, respectively  Table 6 Grades, Components, and Uses of Copper Smelting GradeCodeComposition (%)　Purpose　　copperNot less thantotal impurities Small greater thanNo.1 copperNo.2 copperCu-1Cu-2ninety-nine point nine fiveninety-nine point nine zerozero point zero fivezero point one zeroSuitable for electrolytic copper, for solution casting of copper wire ingots, copper ingots, copper bars, and cast alloysSuitable for copper wire ingots for electrical purposes, used for rolling conductive wires, copper bars, and profiles  Table 7 Groups, grades, and compositions of processed copper formGradeCodeChemical composition (%) by weightTotal impurities (%) by weightPurposeCopper+SilverotherPure copperNo.1 copperNo.2 copperNo.3 copperT1T2T3≥ ninety-nine point nine five≥ ninety-nine point nine zero≥ ninety-nine point seven zero　≤ zero point zero five≤ zero point one zero≤ zero point three zero1. For conductive and high-purity alloys, 2. For conductive use, 3. For general useOxygen free copperNo.1 oxygen free copperNo.2 oxygen free copperTU1TU2　　≤ zero point zero three≤ zero point zero fiveElectric vacuum devices and instrumentsPhosphorus removalOxygen copperNo.1 deoxygenated copperNo.2 deoxygenated copperTP1TP2≥ ninety-nine point nine zero≥ ninety-nine point nine eightPhosphorus 0.005-0.012Phosphorus 0.013-0.050≤ zero point one zero≤ zero point one fiveWelding and other purposesSilver copper0.1 silver copperTAg0.1Copper≥ ninety-nine point nine fiveSilver 0.06-0.12≤ zero point three zero　  2、 Copper alloy& nbsp;& nbsp; (1) Brass& nbsp;& nbsp; Brass is an alloy of copper and zinc. The simplest brass is copper& mdash; Zinc binary alloy, known as simple brass or ordinary brass. Changing the zinc content in brass can yield brass with different mechanical properties. The higher the zinc content in brass, the higher its strength and slightly lower its plasticity. The zinc content of brass used in industry does not exceed 45%, and a higher zinc content will lead to brittleness and deterioration of alloy properties. & nbsp;& nbsp;& nbsp;& nbsp;& nbsp;& nbsp; In order to improve a certain performance of brass, brass added with other alloy elements on the basis of monobasic brass is called special brass. The commonly used alloying elements include silicon, aluminum, tin, lead, manganese, iron, and nickel. Adding aluminum to brass can improve its yield strength and corrosion resistance, while slightly reducing its plasticity. Brass containing less than 4% aluminum has excellent comprehensive properties such as processing and casting. Adding 1% tin to brass can significantly improve its ability to resist seawater and marine atmospheric corrosion, hence it is called&# quo; Navy brass;. Tin can also improve the cutting performance of brass. The main purpose of adding lead to brass is to improve its cutting ability and wear resistance, and lead has little effect on the strength of brass. Manganese brass has good mechanical properties, thermal stability, and corrosion resistance; Adding aluminum to manganese brass can also improve its performance and obtain castings with a smooth surface. Brass can be divided into two types of products: casting and pressure processing& nbsp;& nbsp;& nbsp;& nbsp;& nbsp;& nbsp;& nbsp; (2) Bronze& nbsp;& nbsp; Bronze is the earliest alloy used in history, originally referring to bronze. It is called bronze because of its bluish gray color. In order to improve the technological and mechanical properties of alloys, other alloying elements such as lead, zinc, phosphorus, etc. are also added to most bronze. Due to tin being a scarce element, many tin free Wuxi bronze is also used in industry, which is not only cheap but also has the required special properties. Wuxi bronze mainly includes aluminum bronze, beryllium bronze, manganese bronze, silicon bronze, etc. In addition, there are ternary or quaternary bronze with more complex components. Nowadays, all copper alloys except for brass and white copper (copper nickel alloy) are called bronze. & nbsp;& nbsp;& nbsp;& nbsp;& nbsp; & nbsp; Tin bronze has high mechanical properties, good corrosion resistance, friction reduction, and good casting performance; Low sensitivity to overheating and gases, good welding performance, no ferromagnetism, and low shrinkage coefficient. Tin bronze has higher corrosion resistance than brass in atmosphere, seawater, fresh water, and steam. Aluminum bronze has higher mechanical properties, wear resistance, corrosion resistance, cold resistance, heat resistance, and non ferromagnetism than tin bronze. It has good flowability and no segregation tendency, and can obtain dense castings. Adding elements such as iron, nickel, and manganese to aluminum bronze can further improve the various properties of the alloy& nbsp;& nbsp;& nbsp;& nbsp;& nbsp;& nbsp;& nbsp; (3) White copper & nbsp;& nbsp;& nbsp;& nbsp;& nbsp;& nbsp; Copper based alloys with nickel as the main additive element are silver white and are called white copper. Copper nickel binary alloy is called ordinary white copper, and copper nickel alloy with elements such as manganese, iron, zinc, and aluminum is called complex white copper. Pure copper with nickel can significantly improve strength, corrosion resistance, resistance, and thermoelectric properties. Industrial white copper is divided into two types based on its performance characteristics and uses: structural white copper and electrical white copper, which meet various corrosion resistance and special electrical and thermal properties.