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Copper, yes
Commercial pure copper
. Because of its rose red color, the surface is formed
Oxide film
After purple, it is generally called copper, also known as red copper. It is copper containing a certain amount of oxygen, so it is also called oxygen-containing copper, and sometimes can be seen as copper alloy.
- Chinese name
- Red copper
- Foreign name
- Copper
- alias
- Red copper
- should
- Making conductive and heat-conducting equipment
- Melting point
- 1083 ℃ [3 ]
- density
- 8.96 g/cm³ [3 ]
- Boiling point
- 2360 ℃ [4 ]
Copper, also known as red copper, has good electrical and thermal conductivity, excellent plasticity, easy hot pressing and cold pressure processing, a large number of used in the manufacture of wire, cable, brush, EDM special corrosion of electrical corrosion of copper and other products requiring good electrical conductivity.
The electrical and thermal conductivity of copper is second only to silver, and it is widely used in the production of conductive and thermal equipment. Copper in the atmosphere, seawater and some non-oxidizing acids (hydrochloric acid, dilute sulfuric acid), alkali, salt solution and a variety of organic acids (acetic acid, citric acid), has good corrosion resistance, used in the chemical industry. In addition, copper has good weldability and can be made into various semi-finished products and finished products by cold and thermoplastic processing. In the 1970s, the production of red copper exceeded the total production of all other copper alloys.
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Copper is named for its purplish red color. It's not necessarily
Pure copper
Sometimes a small amount of deoxidation elements or other elements are added to improve the material and performance, so it is also classified
Copper alloy
. Chinese copper processing materials can be divided into: ordinary copper (T1, T2, T3),
Oxygen-free copper
(TU1, TU2 and high purity, vacuum oxygen-free copper),
Deoxidized copper
(TUP, TUMn), add a small amount
Alloying element
Special copper (arsenic copper, tellurium copper, silver copper) four categories. The electrical and thermal conductivity of copper is second only to silver, and it is widely used in the production of conductive and thermal equipment. Copper in the atmosphere, seawater and certain
Non-oxidizing acid
(Hydrochloric acid,
Dilute sulfuric acid
), alkali, salt solution and a variety of organic acids (acetic acid, citric acid) have good corrosion resistance.
Copper is a relatively pure kind of copper, generally can be approximately considered to be pure copper, electrical conductivity, plasticity are better, but the strength, hardness is poor. Copper has excellent thermal conductivity, ductility and corrosion resistance. The trace impurities in copper have a serious effect on the electrical and thermal conductivity of copper. Among them, titanium, phosphorus, iron and silicon significantly reduce the conductivity, while cadmium and zinc have little effect. The solid solubility of sulfur, selenium and tellurium in copper is very small, and can form brittle compounds with copper, which has little effect on electrical conductivity, but can reduce the processing plasticity.
Copper in the atmosphere, seawater and some non-oxidizing acids (hydrochloric acid, dilute sulfuric acid), alkali, salt solution and a variety of organic acids (acetic acid, citric acid), has good corrosion resistance, used in the chemical industry. In addition, copper has good weldability and can be made into various semi-finished products and finished products by cold and thermoplastic processing. In the 1970s, the production of red copper exceeded the total production of all other copper alloys.
The trace impurities in copper have a serious effect on the electrical and thermal conductivity of copper. Among them, titanium, phosphorus, iron and silicon significantly reduce the conductivity, while cadmium and zinc have little effect. The solid solubility of oxygen, sulfur, selenium and tellurium in copper is very small, and can form brittle compounds with copper, which has little effect on electrical conductivity, but can reduce the processing plasticity. Ordinary copper in hydrogen or
Carbon monoxide
the
Reductive atmosphere
During medium heating, hydrogen or carbon monoxide tends to interact with grain boundaries
Cuprous oxide
(Cu)
2
O) effect, produce high pressure water vapor or carbon dioxide gas, can make copper rupture. This phenomenon is often called "copper".
Hydrogen disease
". Oxygen is harmful to the weldability of copper. Bismuth or lead form low melting point eutectic with copper, which makes copper hot brittle. When the brittle bismuth is distributed in thin film at the grain boundary, the copper is cold brittle. Phosphorus can significantly reduce the conductivity of copper, but can increase the fluidity of copper liquid and improve the weldability. Proper amount of lead, tellurium and sulfur can improve machinability. The tensile strength of copper annealed sheet at room temperature is 22 ~ 25 kg force/mm
2
Elongation is 45 ~ 50%, Brinell hardness (HB) is 35 ~ 45.
The thermal conductivity of pure copper is 386.4 W/(m·K).
1. Elastic modulus: Elastic modulus is a measure of the ability of a material to undergo elastic deformation when subjected to a certain stress, expressed by E. The elastic modulus gives the degree of rigidity of a material and is an important parameter of material properties. For red copper, its elastic modulus is about 100-110 GPa.
2. Shear modulus: Shear modulus refers to the ratio of the reaction force and stress generated by the deformation of a material when it is subjected to shear stress, which plays an important role in material mechanics. For copper, the shear modulus is about 45-50 GPa.
3. Poisson's ratio: Poisson's ratio refers to the ratio that a material will expand or contract in superior proportion in two directions perpendicular to this direction when it is subjected to pressure in one direction under isotropic conditions. Poisson's ratio is a value between 0 and 0.5, and for copper, it is about 0.33.
Copper is much more widely used than pure iron, and 50% of copper is purified into pure copper by electrolysis every year for the electrical industry. The copper mentioned here is indeed very pure, containing more than 99.95% copper, and a very small amount of impurities, especially phosphorus, arsenic, aluminum, etc., will greatly reduce the conductivity of copper. It is mainly used in the production of electrical equipment such as generators, busbars, cables, switching devices, transformers, heat exchangers, pipelines, solar heating devices such as plate collectors and other thermal equipment. The oxygen content of copper (it is easy to mix a small amount of oxygen in copper smelting) has a great impact on the conductivity, and the copper used in the electrical industry must generally be oxygen-free copper. In addition, impurities such as lead, antimony and bismuth will make the crystallization of copper cannot be combined together, resulting in hot brittleness, which will also affect the processing of pure copper. This very pure copper is commonly used
Electrolytic method
Refining: the impure copper (that is, crude copper) as the anode, pure copper as the cathode, to
Copper sulfate solution
It is the electrolyte. When the current passes through, the impure copper on the anode gradually melts, and the pure copper gradually settles on the cathode. The copper thus refined. Purity up to 99.99%.
Copper is also used in the production of motor short-circuit rings, electromagnetic heating inductors and high-power electronic components, wiring bar terminals and the like.
Copper is also used in doors, Windows, handrails and other furniture and decoration.
1. Oxy-acetylene welding
Wire 201 (or wire 202) wire and flux 301 can be used for copper oxy-acetylene welding. After 400~700℃ preheating before welding, the welding flame adopts neutral flame and large flame power. Using fewer welding layers, hammer the weld after welding to reduce welding stress.
2, electrode arc welding
Copper 107 or 227 electrode can be selected for arc welding. The power supply adopts DC reverse connection. The preheating temperature before welding is 300~500℃, and the short arc and straight shuttle rod are used during welding. After welding, the welding seam is hammered to reduce the welding stress.
3, argon tungsten arc welding
The welding wire and flux used in argon tungsten arc welding are the same as those used in oxy-acetylene welding, and the power supply is direct current. Preheat before welding, but the temperature should not be too high.
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