Copper bar is a kind of non-ferrous metal processing bar, which has good processing performance and high electrical conductivity. It is mainly divided into brass rod (copper zinc alloy, cheaper) and red copper rod (higher copper content).

The brass rod is a rod-shaped object made of an alloy of copper and zinc. It is named for its yellow color. Brass containing 56% ~ 68% copper has a melting point of 934 ~ 967 degrees. Brass has good mechanical properties and wear resistance, and can be used to manufacture precision instruments, ship parts, cartridge cases of guns and guns, etc.

There will be different colors depending on the zinc content. For example, when the zinc content is 18% - 20%, it will be red yellow, and when the zinc content is 20% - 30%, it will be brown yellow. In addition, the sound of brass is unique, so the eastern gongs, cymbals, bells, horns and other musical instruments, as well as the Western brass instruments, are all made of brass.

classification

Materials: H59, H59-1, h59-2, h59-3, h60, h60-2, H62, h63, H65, H68, H70, H80, H90; C1100, c1020, C2680, C2800, c2600, C2801, C5191, C5210, c2200, c7521, c7541, C17200, c1070, c7701, Qsn6.5-0.1, qsn8-0.3, qsn4-0.3, bzn18-18, bzn15-20, cube2 and many other materials

58-3 copper rod and 59-1 copper rod belong to free cutting brass, which can be divided into environmental protection brass rod and ordinary brass rod. Generally, authentic 58-3 copper bars and 59-1 copper bars are produced by extrusion process. Ordinary continuous casting copper bars can not meet the requirements in all aspects. The copper bars produced by extrusion process have good tensile strength, high hardness and high straightness. Generally, it is used in precision copper parts such as auto parts, medical accessories and electrical accessories.

Application scope

Air conditioning pipes, refrigerator pipes, oil pipes, water supply pipes and various mechanical supporting materials, automobile synchronizer gear rings, marine pumps, valves, structural parts, friction accessories, etc.

(1) All elements without exception reduce the conductivity and thermal conductivity of the copper rod. Any element that is solid dissolved in the copper rod causes lattice distortion of the copper rod, wave scattering when free electrons flow directionally, and increases the resistivity. On the contrary, elements with no or little solid solution in the copper rod have little effect on the conductivity and thermal conductivity of the copper rod. It should be noted that the solid solubility of some elements in the copper rod decreases sharply with the decrease of temperature, The precipitation of single substance and metal compound can not only strengthen the copper bar alloy by solid solution and dispersion, but also reduce the conductivity little. This is an important alloying principle for the study of high strength and high conductivity alloys. It should be specially pointed out here that the alloy composed of iron, silicon, zirconium (not wrong), chromium and copper bar is an extremely important high strength and high conductivity alloy; Because the influence of alloying elements on the properties of copper bars is superimposed, CoCr Zr alloys are famous high strength and high conductivity alloys.

(2) The structure of copper base corrosion-resistant alloy should be single phase to avoid electrochemical corrosion caused by the second phase in the alloy. Therefore, the added alloy elements should have a large solid solubility in the copper bar, and even be infinitely miscible elements. The single-phase brass bar, bronze bar and white copper bar used in engineering have excellent corrosion resistance and are important heat exchange materials.

(3) There are both soft phase and hard phase in the structure of copper based wear-resistant alloy. Therefore, during alloying, it must be ensured that in addition to solid solution of the added elements in the copper bar, there should also be hard phase precipitation. The typical hard phases in the copper bar alloy are Ni3Si, fealsi compounds, etc., and the a phase should not be more than 10%.

(4) Copper bar alloys with polycrystalline transformation in the solid state have damping properties, such as Cu Mn alloys. Alloys with thermoelastic martensitic transformation in the solid state have memory properties, such as Cu Zn Al and Cu al Mn alloys.

(5) The color of the copper bar can be changed by adding alloying elements, such as zinc, aluminum, tin, nickel and other elements. With the change of content, the color will also change from red to blue to yellow and white. If the content is reasonably controlled, gold imitating materials and silver imitating alloys can be obtained.

(6) The elements selected for the alloying of copper bars and alloys should be common, cheap and pollution-free. The added elements should be based on the principle of multi-element and small amount. The alloy raw materials can be comprehensively utilized. The alloy should have excellent process performance and be suitable for processing into various finished products and semi-finished products.