Copper is a chemical element, its chemical symbol is Cu, its atomic number is 29, and it is a transition metal. The most common use of copper is in making wires. Usually, the wires used today are made of pure copper because its electrical and thermal conductivity are second only to silver, but it is much cheaper than silver.
Common categories
Many people think that there is only one kind of copper. It's the only one. But there are actually other different types of copper. For example, alloy copper; brass is an alloy composed of copper and zinc; white copper is an alloy of copper and nickel; bronze is an alloy formed of copper and elements other than zinc and nickel, mainly tin bronze, aluminum bronze, etc.; Red copper is copper with a high copper content, and the total content of other impurities is less than 1%.
Classification of copper processed materials: Copper sulfate, copper chloride, copper bar, copper bar, copper ingot, copper plate, copper wire, copper alloy, rough copper, copper strip, copper oxide, copper foil, copper tube, copper foil, copper paste, copper casting, electrolytic copper, other copper alloy copper materials.
Made of pure copper or copper alloy, various shapes including rods, wires, plates, strips, tubes, foils, etc. are collectively referred to as copper.There are methods for processing copper materials such as rolling, extrusion and drawing. Plates and strips in copper materials are hot rolled and cold rolled; strips and foils are cold rolled; pipes and bars are divided into extruded products and drawn products; wire rods are drawn products.
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pure copper
Pure copper is a rose-red metal. It turns purple after forming a copper oxide film on its surface. Therefore, industrial pure copper is often called copper or electrolytic copper.The density is 8~9g/cm?, Melting point 1083℃. Pure copper has good electrical conductivity and is used in large quantities to make wires, cables, brushes, etc.; it has good thermal conductivity and is often used to make magnetic instruments and instruments that must be protected from magnetic interference, such as compasses, aviation instruments, etc.; it has excellent plasticity and is easy to hot pressed and cold processed, and can be made into copper materials such as pipes, rods, wires, strips, strips, plates, foils, etc. Pure copper products include smelted products and processed products.
China's red copper processing materials can be divided into four categories according to composition: ordinary red copper (T1, T2, T3, T4), oxygen-free copper (TU1, TU2 and high-purity, vacuum oxygen-free copper), deoxygenated copper (TUP, TUMn), and special copper (arsenic copper, tellurium copper, and silver copper) added with a small amount of alloying elements.
Pure copper's electrical and thermal conductivity are second only to silver, and is widely used to make conductive and thermally conductive equipment. Red copper has good corrosion resistance in the atmosphere, seawater, certain non-oxidizing acids (hydrochloric acid, dilute sulfuric acid), alkali, salt solutions and various organic acids (acetic acid, citric acid), and is used in the chemical industry. In addition, red copper has good weldability and can be made into various semi-finished products and finished products through cold and hot plastic processing. In the 1970s, the output of copper exceeded the total output of other copper alloys.
Trace impurities in pure copper significantly affect the electrical and thermal conductivity of copper. Elements such as titanium, phosphorus, iron, and silicon greatly reduce the electrical conductivity, while elements like cadmium and zinc have little impact. Oxygen, sulfur, selenium, and tellurium have very low solubility in copper; they can form brittle compounds with copper, which have little effect on electrical conductivity but can reduce the plasticity of the material during processing. When ordinary red copper is heated in a reducing atmosphere containing hydrogen or carbon monoxide, hydrogen or carbon monoxide easily reacts with the oxide Cu2O at the grain boundaries, producing high-pressure water vapor or carbon dioxide gases, which can cause the copper to crack. This phenomenon is often referred to as “hydrogen disease” in copper. Oxygen is harmful to the weldability of copper. Bismuth or lead forms low-melting eutectics with copper, causing thermal brittleness in the copper; when bismuth is distributed in thin films at the grain boundaries, it causes cold brittleness in the copper. Phosphorus significantly reduces the electrical conductivity of copper, but it can improve the fluidity of the copper melt and enhance weldability. Appropriate amounts of lead, tellurium, and sulfur can improve the machinability of copper.
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brass
Brass is an alloy of copper and zinc. The simplest brass is a binary alloy of copper and zinc, called simple brass or ordinary brass. Changing the zinc content in brass can obtain brass with different mechanical properties. The higher the zinc content in brass, the higher its strength and lower its plasticity. The zinc content of brass used in the industry does not exceed 45%. No matter how high the zinc content is, it will produce brittleness and deteriorate the alloy properties. Brass can be divided into two types of products: casting and pressure working.
The brass is divided into two parts:
1) Ordinary brass
It is an alloy composed of copper and zinc. When the zinc content is less than 39%, zinc can be dissolved in copper to form single-phase a, which is called single-phase brass. It has good plasticity and is suitable for hot and cold pressure processing. When the zinc content is greater than 39%, there is a single phase and a copper-zinc-based b solid solution, called dual-phase brass. b makes the plasticity small and the tensile strength increase, which is only suitable for hot pressure processing.
The code name is represented by "H+ number", H represents brass, and the number represents the mass fraction of copper. For example, H68 means brass with a copper content of 68% and a zinc content of 32%; cast brass has the word "Z" before the code name, such as ZH62.
H90 and H80 are single-phase, golden yellow, so they are called gold together, called plating, decoration, medal, etc. H68 and H59 are dual-phase brass and are widely used in structural parts on electrical appliances, such as bolts, nuts, washers, springs, etc.
In general, single-phase brass is used for cold deformation processing, and dual-phase brass is used for hot deformation processing.
2) Special brass
A multi-element alloy composed of ordinary brass by adding other alloying elements is called brass. Elements often added include lead, tin, aluminum, etc., which can be called lead brass, tin brass, and aluminum brass accordingly. The purpose of adding alloying elements. It is mainly to improve tensile strength and improve processability.
Code: It is expressed as "H+ main additive element symbol (except zinc)+ mass fraction of copper + mass fraction of main additive element + mass fraction of other elements".
For example, HPb59 -1 means that the mass fraction of copper is 59%, the mass fraction of lead containing the main additive element is 1%, and the balance is zinc.
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bronze
Bronze is the earliest alloy used in history. It originally refers to copper-tin alloy. Because of its bluish-gray color, it is called bronze. In order to improve the technological and mechanical properties of the alloy, other alloying elements, such as lead, zinc, phosphorus, etc., are added to most bronzes. Since tin is a scarce element, many tin-free Wuxi bronzes are still used in the industry. They are not only cheap, but also have required special properties. Bronze is also divided into two categories: pressure working and casting products.
Code: The expression method is composed of "Q+ main additive element symbol and mass fraction + mass fraction of other elements". For cast products, the word "Z" is added before the code name. For example, Qal7 means that the aluminum bronze containing 5%, and the rest is copper ZQsn10 -1 means that the tin content is 10%, and the content of other alloy elements is 1%. The balance is copper cast tin bronze. Bronze can be divided into two categories: tin bronze and special bronze (i.e. Wuxi bronze).
(1) It is a copper-tin alloy with tin as the main additive element, also known as tin bronze
When the tin content is less than 5 - 6%, tin dissolves in copper to form a solid solution, and the plasticity increases. When the tin content is more than 5 - 6%, due to the appearance of Cu31Sb8-based solid solution, the tensile strength decreases, so the tin content of tin bronzes is mostly between 3 and 14%. When the tin content is less than 5%, it is suitable for cold deformation processing, and when the tin content is 5 - 7%, it is suitable for hot deformation processing. When the tin content is greater than 10%, it is suitable for casting.
Since a is close to the electrode potential, and tin in the composition is nitrided to form a dense tin dioxide film, its corrosion resistance to atmosphere, seawater, etc. is increased, but its acid resistance is poor.
Because tin bronze has a wide crystallization temperature range and poor flowability, concentrated shrinkage cavities are not easy to form, but dendritic segregation and scattered shrinkage cavities are easy to form, and the casting shrinkage rate is small, which is conducive to obtaining castings with a size very close to that of the mold. Therefore, it is suitable for casting conditions with complex shapes and large wall thicknesses, but not suitable for casting castings requiring high density and good sealing properties. Tin bronze has good anti-friction properties, diamagnetism and low-temperature toughness. Tin bronze can be divided into two categories according to production methods: pressure processed tin bronze and cast tin bronze.
A. Pressure-processed tin bronze
The tin content is generally less than 8%. It is suitable for processing into various profiles such as plates, strips, rods, and tubes under both hot and cold conditions. After hardening, its tensile strength and hardness increase, while plasticity decreases. Upon re-tempering, it can maintain high tensile strength while improving plasticity, especially achieving high elastic limits. This material is ideal for components that require resistance to corrosion and wear, elastic parts, magnetic-resistant components, as well as sliding bearings and bushings in machinery. Common grades include Qsn4-3 and Qsn6.5~0.1.
B. Casting tin bronze
It is supplied as ingots and cast into castings by the casting shop. It is suitable for casting castings with complex shapes but low density requirements, such as sliding bearings, gears, etc. Commonly used ones are ZQsn10 -1 ZQsn6 -6-3.
2)special bronze
Add other elements to replace tin, or make Wuxi bronze. Most special bronzes have higher mechanical properties, wear resistance and corrosion resistance than tin bronze. Commonly used ones are aluminum bronze (QAL7 QAL5) lead bronze (ZQPB30), etc.
Copper-based alloys with nickel as the main added element are silvery white and are called white copper. The nickel content is usually 10%, 15%, and 20%. The higher the content, the whiter the color. The copper-nickel binary alloy is called ordinary white copper, and the copper-nickel alloy containing elements such as manganese, iron, zinc and aluminum is called complex white copper. The addition of pure copper and nickel can significantly improve the strength, corrosion resistance, resistance and thermoelectric properties. Industrial white copper is divided into structural white copper and electrical white copper according to different performance characteristics and uses, which respectively meet various corrosion resistance and special electrical and thermal properties.
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cupronickel
Copper-based alloys with nickel as the main added element are silvery white and are called white copper. The copper-nickel binary alloy is called ordinary white copper, and the copper-nickel alloy containing elements such as manganese, iron, zinc and aluminum is called complex white copper. The addition of pure copper and nickel can significantly improve the strength, corrosion resistance, resistance and thermoelectric properties. Industrial white copper is divided into structural white copper and electrical white copper according to different performance characteristics and uses, which respectively meet various corrosion resistance and special electrical and thermal properties.
discrimination method
White copper, brass, red copper (also known as "copper"), and bronze (bluish gray or grayish yellow) are distinguished in color. Among them, white copper and brass are easy to distinguish; red copper is pure copper (impurities 1%) and bronze (other alloy components about 5%) is slightly difficult to distinguish. When not oxidized, red copper is brighter than bronze, and bronze is slightly cyan or darker yellow; after oxidation, red copper turns black, and bronze turns turquoise (harmful oxidation due to too much water) or chocolate color.
Copper was the earliest metal used by human ancestors. It has many excellent characteristics and wonderful functions, which not only makes indelible contributions to the progress of human society, but also continuously develops new uses with the development of human civilization. Copper is both an ancient metal and a modern engineering material full of vitality and vitality. At present, mankind has entered a colorful and highly civilized society characterized by electrification and electronic information, opening up a broader land for the application and use of copper.
Why use copper and what properties are mainly used?Copper has excellent electrical and thermal conductivity, ranking first among all engineering metal materials. This is the main basis for its pivotal role in the current electrification and electronic information society. Copper also has many excellent comprehensive properties: it has strong corrosion resistance to the atmosphere, sea water, soil and many chemical media; it is used in structures that are both rigid and soft, elastic, resistant to friction and wear; it has a colorful appearance, which is a symbol of simplicity and elegance that people love. In addition to the above-mentioned many performance properties, it also has a series of good processing, casting, welding, easy cutting and other process properties, which makes it economically and widely used.
--Housing construction accounted for 48%:Including: piping system (water, heat, gas, fire sprinklers, etc.); house facilities (air conditioners, refrigerators, etc.); building decoration (roof, flow channels, decoration, etc.); communication lines (sound, image, data, etc.); power supply system.
--Equipment production accounted for 41%:Including: industrial equipment (motors, transformers, etc.); transportation (automobiles, railways, aircraft, etc.); electronic devices; light industrial products (household appliances, instruments, tools, etc.)
- Infrastructure 11 per cent:Including: large-scale projects (transportation facilities, petrochemical industry, mining and smelting industry, etc.); power utilities (transmission, distribution, etc.); communication networks.
It is worth noting that housing construction is directly related to the improvement of people's production levels, and the application of copper in this regard accounts for the largest proportion; especially my country regards housing construction as an important link in stimulating the development of the entire national economy. It can be seen that actively Promote the important role of copper in the national economy and people's livelihood.
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Applications in the electrical industry
※ Power transmission
Power transmission requires a large amount of copper, which consumes high conductivity, and is mainly used for power, wires and cables, busses, transformers, switches, plug-in components and connectors.
During the transmission of wires and cables, electrical energy is wasted due to resistance heating. From the perspective of energy conservation and economy, the "better cable section" standard is currently being promoted in the world." The "Better Cable Section" standard takes into account the two factors of one-time installation cost and power consumption, and appropriately enlarges the cable size to achieve the purpose of energy conservation and better comprehensive economic benefits. According to the new standard, the cross-section of the cable is often more than double that of the old standard, and an energy-saving effect of about 50%.
In the past, my country has taken measures to replace copper with aluminum in overhead high-voltage transmission lines hoping to reduce weight due to the short supply of steel. Considering that the proportion of aluminum is only 30% of copper, considering that the proportion of aluminum is only 30% of copper. Currently, for environmental protection considerations, air transmission lines will be converted to underground cables. In this case, aluminum is dwarfed by copper because of its poor conductivity and large cable size.
For the same reason, it is also a wise choice to replace the aluminum winding transformers in the United States and Japan with energy-saving and efficient copper-winding transformers.
※ Motor manufacturing
In motor manufacturing, copper alloys with high conductivity and high strength are widely used. The main parts used for copper are the stator, rotor and shaft head. In large motors, the windings need to be cooled with water or hydrogen, which is called dual water internal cooling or hydrogen cooling motors, which requires large lengths of hollow wires.
Motors are a large user of electricity, accounting for about 60% of the total electricity supply. The cumulative electricity bill for running a motor is very high, and it generally reaches the cost of the motor within the first 500 hours of operation, which is equivalent to 4 to 16 times the cost within one year, and can reach 200 times the cost during the entire working life. A small increase in motor efficiency can not only save energy, but also achieve significant economic benefits. The development and application of high-efficiency motors is currently a hot topic in the world. Since the energy consumption inside the motor mainly comes from the resistance loss of the windings, increasing the cross-section of the copper wire is a key measure to develop efficient motors. Compared with traditional motors, some high-efficiency motors that have been first developed in recent years have increased the use of copper windings by 25 to 100%. Currently, the U.S. Department of Energy is funding a development project to produce motor rotors using cast-in-copper technology.
※ Communication cable
Since the 1980s, due to the advantages of large current-carrying capacity of optical fiber cables, they have continuously replaced copper cables on communication trunks and have been rapidly promoted and applied. However, converting electricity into light energy and inputting it to users still requires large amounts of copper. With the development of communications, people are increasingly dependent on communications,Demand for fiber optic cables and copper wires will continue to increase.
※ Residential electrical lines
In recent years, with the improvement of people's living standards in our country, home appliances have been rapidly popularized, and residential electricity loads have increased rapidly. my country's residential electricity consumption will still develop greatly in the future, which will also greatly increase the application of copper wires.
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Applications in the electronics industry
The electronics industry is an emerging industry. In its booming development process, new steel products and new application fields have been continuously developed. At present, its application has developed from electrical vacuum devices and printed circuits to microelectronics and semiconductor integrated circuits.
※ Electric vacuum device
Electric vacuum devices are mainly high-frequency and ultra-high frequency transmitter tubes, waveguides, magnetrons, etc. They require high-purity oxygen-free copper and dispersion-strengthened oxygen-free copper.
※ Printed circuit
Copper printed circuits use copper foil as a surface and paste it on a plastic plate serving as a support; the circuit wiring diagram is printed on copper plates by photography; excess parts are removed by etching to leave interconnected circuits.Then, holes are drilled at the connection points between the printed circuit board and external components. The terminals of the discrete components are inserted into these holes, and then soldered onto them. In this way, a complete circuit is assembled. If immersion plating method is used, all soldering can be completed in one go. This makes printed circuits ideal for applications where precise circuit layout is required, such as in radios, televisions, and computers. Printed circuits can significantly reduce the amount of wiring and assembly work required, thus they are widely used. However, this process requires a significant amount of copper foil. Additionally, various low-cost, low-melting-point, and highly malleable copper-based brazing materials are needed for connecting the circuits together.
※ Integrated circuit
The core of microelectronics technology is the integrated circuit. An integrated circuit refers to a miniature circuit in which components and interconnects that make up a circuit are integrated onto a semiconductor substrate using specialized manufacturing techniques. These microcircuits are thousands of times smaller in size and weight compared to the most compact discrete component circuits. The advent of integrated circuits has brought about a significant transformation in computers, becoming the foundation of modern information technology. Currently, advanced large-scale integrated circuits can incorporate tens of thousands, or even millions, of transistors on a single chip smaller than a fingernail. Recently, the internationally renowned computer company IBM (International Business Machines Corporation)…Progress has been made in replacing aluminum with copper as the interconnect material in silicon chips. This new type of microchip can achieve a 30% performance improvement. The line dimensions of the circuits can be reduced to 0.12 micrometers, allowing for the integration of up to two million transistors on a single chip. This represents a significant breakthrough for the use of copper, a traditional metal, in this latest field of semiconductor integrated circuits.
※ Lead frame
In order to ensure the proper functioning of integrated circuits or hybrid circuits, it is necessary to encapsulate them. During this process, numerous connections in the circuit must be led out from within the encapsulation structure. These leads need to be strong enough to serve as the structural framework supporting the integrated circuit, and this structure is known as a lead frame. In actual production, for high-speed mass production purposes, lead frames are typically manufactured by stamping metal sheets in a specific arrangement. The material used for the lead frames accounts for one-third to one-quarter of the total cost of an integrated circuit, and since such materials are consumed in large quantities, it is essential to achieve low costs.
Copper alloy is cheap, has high strength, electrical conductivity and thermal conductivity, and has excellent processability, brazing properties and corrosion resistance. Its performance can be controlled in a wide range through alloying, which can better meet the performance requirements of lead frames. It has become an important material for lead frames. It is currently the most used material of steel in microelectronic devices.
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Applications in the energy and petrochemical industries
※ Energy industry
Both thermal power and atomic power generation rely on steam to do work. The steam circuit is as follows:
Steam generated in the boiler-the steam drives the steam turbine to do work-the steam after working is sent to the condenser-cooled into water-returns to the boiler and becomes steam again.
During this period, the main condenser consists of tubesheet and condenser tubes. Because steel has good thermal conductivity and resistance to water corrosion, they are made of pot brass, aluminum brass or white copper. According to the data, 5 tons of condenser pipes are required per 10,000 kilowatts of installed capacity. A 600,000-kilowatt power plant requires 300 tons of condensing pipes.
The utilization of solar energy also requires the use of many copper pipes.For example, a swimming pool in a hotel near London, England, is equipped with solar heaters that can keep the water temperature at 18 - 24 ° C in summer. The solar heater contains 784 pounds (356 kilograms) of copper tubing.
※ Petrochemical industry
Copper and many copper alloys have good corrosion resistance in aqueous solutions, non-oxidizing acids such as hydrochloric acid, organic acids (such as acetic acid, citric acid, fatty acids, lactic acid, oxalic acid, etc.), various bases other than ammonia and non-oxidizing organic compounds (such as oils, phenols, alcohols, etc.); Therefore, it is widely used in the petrochemical industry to manufacture various containers, piping systems, filters, pumps, valves and other devices that come into contact with corrosive media. Its thermal conductivity is also used to make various evaporators, heat exchangers and condensers. Due to its good plasticity, copper is especially suitable for manufacturing heat exchangers with complex structures and crossed copper pipes in the modern chemical industry. In addition, bronze production tools are used in petroleum refineries; originally, sparks are not emitted during impact, which can prevent fires.
※ Marine industry
The ocean accounts for more than 70% of the earth's surface area, and the rational development and utilization of marine resources is receiving increasing attention. Seawater contains chloride ions that are easy to cause corrosion. Many engineering metal materials such as steel, aluminum, and even stainless steel are not resistant to seawater corrosion. In addition, marine biofouling will also form on the surfaces of these materials, as well as non-metallic materials such as wood and glass.Copper stands out, not only resisting seawater corrosion, but also the copper ions dissolved in water have a bactericidal effect and can prevent marine biofouling.Therefore, copper and copper alloys are very important materials in the marine industry and have been widely used in desalination plants, marine oil and gas production platforms, and other coastal and seabed facilities. For example, piping systems, pumps and valves used in seawater desalination, as well as equipment used on oil and gas production platforms, including bolts for splash zones and underwater, drilling days, anti-biofouling envelopes, pump valves and piping systems, etc.
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Applications in the transportation industry
※ Ship
Due to their good resistance to seawater corrosion, many copper alloys such as aluminum bronze, manganese bronze, aluminum brass, gun copper (tin-zinc bronze), white copper and nickel-copper alloy (Monel alloy) have become standard materials for shipbuilding.Generally, copper and copper alloys account for 2 to 3% of the dead weight of warships and merchant ships.
The propellers of warships and most large merchant ships are made of aluminum bronze or brass.Each propeller of a large ship weighs 20 to 25 tons. The propellers of the USS Queen Elizabeth and USS Queen Mary each weigh 35 tons. "Admiral" gun copper is often used for the heavy stern shafts of large ships, and the same material is used for the conical bolts of the rudder and propeller. Copper and copper alloys are also widely used in engine and boiler rooms. The world's first nuclear-powered merchant ship used 30 tons of white copper condenser pipes.Recently, aluminum brass pipes have been used as large heating coils for oil tanks.There are 12 such storage tanks on a 100,000-ton ship, and the corresponding heating system is quite large. The ship's electrical equipment is also complex, with engines, motors, communications systems, etc. almost entirely dependent on copper and copper alloys to work. The cabins of large and small ships are often decorated with copper and copper alloys. Even wooden boats are best fixed to the wooden structure with copper alloy (usually silicon bronze) screws and nails, which can be mass-produced by rolling.
In order to prevent the hull from being affected by sea biofouling and affecting navigation, copper was often used to protect it; now, copper-containing paint is commonly used to solve the problem.
During World War II, in order to prevent attacks on ships by German magnetic mines, an anti-magnetic mine device was developed. A ring of copper tape was attached around the steel hull, and current was applied to neutralize the ship's magnetic field, so that the mine could not be detonated.
※ Car
Copper used for automobiles is 10 to 21 kilograms per vehicle, which varies according to the type and size of the car. For cars, it accounts for about 6 to 9% of the dead weight.Copper and copper alloys are mainly used in radiators, brake system piping, hydraulics, gears, bearings, brake friction plates, power distribution and power systems, washers, and various joints, accessories and trim.Among them, the one that uses a large amount of copper is the radiator. Modern tube and strip radiators use brass strips to weld the radiator tubes and thin copper strips to bend them into the fins.
In recent years, many improvements have been made in order to further improve the performance of copper radiators and enhance its competitiveness against aluminum radiators. In terms of materials, trace elements are added to copper to increase its strength and softening point without losing thermal conductivity, thereby reducing the thickness of the strip and saving steel consumption; in terms of manufacturing processes, high-frequency or laser welding copper pipes and replacing solder soldering that is susceptible to lead contamination to assemble the radiator core. Compared with brazed aluminum radiators, under the same heat dissipation conditions, that is, under the same pressure drop of air and coolant, the new copper radiator is lighter in weight and significantly reduced in size; coupled with the good corrosion resistance of steel and long service life, the advantages of copper radiators are even more obvious.
※ Railway
Railway electrification requires a large amount of copper and copper alloys. Each kilometer of overhead conductors requires more than 2 tons of shaped copper wire. In order to increase its strength, a small amount of copper (about 1%) or silver (about of%) is often added. In addition, the motors, rectifiers, and control, braking, electrical and signaling systems on trains all rely on copper and copper alloys to work.
※ Aircraft
Aircraft navigation is also inseparable from copper. For example, copper is used for wiring, hydraulic, cooling and pneumatic systems in aircraft, aluminum and bronze pipes are used for bearing holders and landing gear bearings, diamond-resistant steel alloys are used for navigation instruments, and copper-broken elastic elements are used in many instruments, etc.
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Applications in the mechanical and metallurgical industries
※ Mechanical engineering
Copper parts can be found in almost all machines. In addition to the large amount of steel used in motors, circuits, oil pressure systems, air pressure systems and control systems, there are a wide variety of transmission parts and fixing parts made of brass and bronze, such as gears, worm wheels, worms, couplings, fasteners, twisting parts, screws, nuts, etc., everywhere. Bearings or bushings made of friction-reducing copper alloy must be used between almost all parts undergoing relative mechanical movement. In particular, the cylinder liners and sliding plates of large extruders and forging presses of a 10,000-ton class are almost all made of bronze. The weight of the castings can reach several tons. Almost all elastic elements use silicon bronze and tin bronze as materials. Welding tools, die-casting molds, etc. are more inseparable from copper alloys, and so on.
※ Metallurgical equipment
The metallurgical industry is a large consumer of electricity and is known as the "electric tiger". In the construction of a metallurgical plant, it is usually necessary to have a huge transmission and distribution system and power operating equipment that rely on copper for work. In addition, in pyrometallurgy, continuous casting technology has occupied a dominant position. The key component of it, the mold, mostly uses copper alloys with high strength and high thermal conductivity such as chromium copper and silver copper. Vacuum arc furnaces and electroslag furnace water-cooled crucibles in electrometallurgy are made of steel pipes. Various induction heating induction coils are wound with copper pipes or special-shaped copper pipes, and water is cooled inside.
※ Alloy additives
Copper is an important additive element in alloys such as steel and aluminum. Adding a small amount of copper (0.2 - 0.5%) to low-alloy structural steel can improve the strength and atmospheric and marine corrosion resistance of the steel. Adding copper to corrosion-resistant cast iron and stainless steel can further improve their corrosion resistance. High-nickel alloys containing about 30% copper are well-known high-strength and corrosion-resistant "Monel" and are widely used in the nuclear industry.
Many high-strength aluminum alloys contain copper. Through quenching and aging treatment, fine particles are dispersed throughout the alloy, significantly enhancing its strength. This phenomenon is known as age-hardening of aluminum alloys. A well-known example is Durata aluminum, also known as hard aluminum. It is an aluminum alloy containing copper, manganese, and magnesium. It is used as an important structural material in the manufacture of airplanes and rockets.
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Applications in light industry
Light industry products are closely related to people's lives, with a wide variety and variety. Because copper has good comprehensive properties, it can be seen everywhere.
※ Air conditioner and freezer
The temperature control effect of air conditioners and freezers is mainly achieved through the evaporation and condensation of copper pipes in heat exchangers. The size and heat transfer performance of heat exchange tubes largely determine the efficiency and miniaturization of the entire air conditioner and refrigeration device. The special-shaped copper pipes with high thermal conductivity are used on these machines. Taking advantage of the good processability of copper, heat radiating tubes with internal grooves and high fins have been recently developed and produced. They are used to manufacture heat exchangers in air conditioners, freezers, chemical industries and waste heat recovery equipment. The total heat transfer coefficient of new heat exchangers has been increased to 2 - 3 times that of ordinary tubes, and 1.2 - 1.3 times that of ordinary low-fin tubes. It has been used in China, which can save 40% of copper and reduce the volume of the heat exchanger by more than 1/3.
※ Clock
Most of the working parts of clocks, timepieces and devices with clockwork currently produced are made of "clockwork". The alloy contains 1.5-2% lead and has good processability and is suitable for large-scale production. For example, gears are cut out of long extruded brass rods, flat wheels are punched out of strip of corresponding thickness, engraved watch faces, screws and joints are made of brass or other copper alloys, etc. A large number of cheap watches are made of gun copper (tin-zinc bronze) or plated with nickel silver (white copper).Some famous clocks are made of steel and copper alloys. The hour hand of the British "Big Ben" uses a solid gun-bronze rod, and the minute hand is a 14-foot-long copper pipe.
A modern watch factory,Copper alloy is the main material, using presses and precise mold processing, 10,000 to 30,000 clocks can be produced every day at a very low cost.
※ Papermaking
In the current society with ever-changing information, paper consumption is large. The surface of the paper may seem simple, but the papermaking process is complex, requiring many steps and using many machines, including coolers, evaporators, beaters, paper machines, etc. Many of these parts, such as various heat exchange tubes, rollers, striking bars, semi-liquid pumps and wire screens, are mostly made of copper alloys.
For example, currently used Fourdrinier wire paper machines spray the prepared pulp onto a fast-moving mesh cloth with fine meshes (40 - 60 mesh). The mesh cloth is woven from brass and phosphor bronze wire. It has a large width, usually more than 20 feet (6 meters), and is required to be completely straight. The mesh moves on a series of small brass or copper rollers, and moisture is sucked out from below as it passes with the pulp sprayed onto it. The net vibrates simultaneously to bond the small fibers in the pulp together. The size of the mesh on large paper machines is large, reaching a width of 26 feet 8 inches (8.& nbsp;1 meter) and 100 feet long (30.& 5 meters). Wet pulp not only contains water, but also contains chemicals used in the papermaking process, which is very corrosive. In order to ensure the quality of paper, the requirements for mesh materials are very strict, which not only must have high strength and elasticity, but also must be resistant to pulp corrosion. Copper alloy is fully qualified.
※ Printing
In printing, copperplate is used for photocopying. The polished copper plate is sensitized with photosensitive emulsion and photographed and imaged on it.The photosensitive copperplate needs to be heated to harden the glue. In order to avoid softening by heat, copper often contains a small amount of silver or arsenic to increase the softening temperature. The plate is then etched to form a printing surface with a pattern of bumps and bumps distributed.
On automatic typesetting machines, patterns are created by arranging brass type blocks, which is another important use of copper in printing. The typeface blocks are usually made of lead-containing brass, but sometimes copper or bronze.
※ Brewing
Copper plays an important role in the world's beer brewing.Copper is often used as the inner village of malt barrels and fermenters。There are more than a dozen such vats with a capacity of more than 20,000 gallons in some famous breweries. In the fermentation tank, in order to cool down, water pipes are often used to cool down. Steel pipes are also used to pass water steam to heat beer while brewing, and steel pipes are used to transport liquor.
When distilling whiskey and other spirits, a steel still pot is usually used. Whisky malt liquor is distilled twice, using two large copper still pans.
※ Medicine
In the pharmaceutical industry, various steaming, boiling, vacuum devices, etc. are made of pure copper. Zinc white copper is widely used in medical devices. Copper alloy is also a common material for eyeglass frames.
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Copper for architecture and art
※ Pipeline system
Because copper water pipes have many advantages such as beauty and durability, easy installation, safety and fire protection, and health care, they have a significantly superior price-performance ratio compared with galvanized steel pipes and plastic pipes. In residential and public buildings, water supply, heating, gas supply and fire sprinkler systems are increasingly favored and have become the current preferred material. In developed countries, copper water supply systems account for a large proportion. The Manhattan Building in New York, the United States, which is known as the sixth-tallest building in the world, uses 60,000 feet (10,000 kilometers) of copper pipes for its water supply system alone. In Europe, a large amount of steel pipes for drinking water is consumed. The average consumption of drinking water steel pipes in the UK is 1.6 kilograms per person per year, compared with 0.2 kilograms in Japan.Because galvanized steel pipes are prone to rust, many countries have banned them. It is imperative for my country to promote the use of copper piping systems in housing construction.
※ House decoration
There is a tradition in Europe to use through-slabs to make roofs and leaky eaves. It is even used for wall decoration in Nordic countries. Copper has good resistance to atmospheric corrosion, is durable, and can be recycled. It has good processability and can be easily made into complex shapes, and it also has beautiful colors; therefore, it is very suitable for use in house decoration. It has a long history of being used on the roofs of ancient buildings such as churches and still exudes an attractive luster; and it is also being used more and more in the construction of modern large-scale buildings and even apartments and residences. For example: in London, the "Commonwealth Council" Building, which represents modern British architecture, has a complex roof shape and is built of copper plates and weighs about 25 tons; the Crystal Palace Sports Center, which opened in 1966, is made of 60 tons of copper into a wavy roof and so on. According to statistics, the average consumption of copper plates used as roofs is 0.8 kilograms per person per year in Germany and 0.2 kilograms in the United States.
In addition, the decoration of the house, such as door handles, locks, hundreds of pages, press bars, lights, wall decorations and kitchen accessories, etc., uses steel products not only durable and disinfected, but also decorated with an elegant atmosphere, which is deeply loved by people.
※ Statues and handicrafts
There is no other metal in the world that can be used as widely as copper to make various handicrafts. It has lasted for a long time since ancient times. In today's urban construction,A large number of cast copper alloys are used for various souvenirs, cast bells, treasure tripods, statues, Buddha statues, antique products, etc.Modern musical instruments such as flutes are made of white copper and saxophone is made of brass. Various exquisite works of art, cheap and cheap gold plating, and imitation gold and silver jewelry also require the use of copper alloys with various compositions.
The Hong Kong Temple of Heaven Buddha built in 1996 is made of tin, zinc and lead bronze casting. It is 26 meters high and weighs 206 tons. The Nanhai Guanyin Buddha in Putuo Mountain, Zhejiang Province, completed in 1997. It is 20 meters high and weighs 70 tons. It is the world's first giant bronze statue built using imitation gold materials. Later, an 88-meter-high bronze Buddhist statue of Muni was completed in Wuxi.
※ Coins
Since human ancestors used coins for transactions, copper and copper alloys have been used to make coins, which has been passed down through generations and continues to this day. With the development of modern activities such as automatic coin phones, rides and shopping, the amount of steel used for coinage has increased.
In the application of copper coins, in addition to changing the size, it is convenient to use different alloy compositions and change the alloy color to make and distinguish currencies of different denominations. Commonly used are "silver coins" containing 25% nickel, yellow copper coins containing 20% zinc and 1% tin, and "copper" coins containing small amounts of tin (3%) and zinc (1.5%). Thousands of tons of copper are consumed every year to produce copper coins around the world. The Royal Mint in London alone produces 700 million copper coins every year, requiring about 7,000 tons of metal.
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High-tech applications
Copper is not only widely used in traditional industries, but also plays an important role in emerging industries and high-tech fields. Examples are as follows:
※ Computer
Information technology is the forerunner of high technology. It relies on the crystallization of human intelligence—the computer—as a tool for processing and manipulating the vast amounts of information that are constantly changing. The heart of a computer consists of microprocessors (which include arithmetic units and controllers), along with memory components. These basic components are all made up of large-scale integrated circuits, with millions of interconnected transistors, resistors, capacitors, and other elements distributed across tiny chips. These integrated circuits must be assembled using lead frames and printed circuit boards in order to function properly. As can be seen from the previous chapter on “Applications in the Electronics Industry,”Copper and copper alloys are not only important materials in lead frames, solder, and printed circuit boards; they can also play an important role in the interconnection of tiny components in integrated circuits。
※ Superconductivity and low temperature
The resistance of general materials (except semiconductors) decreases with temperature, and when the temperature drops very low, the resistance of some materials disappears completely, which is called superconductivity. The highest temperature at which superconductivity occurs is called the superconducting critical temperature of the material. The discovery of superconductivity opened a new ground for the exploitation of electricity. Back to zero resistance, as long as a small voltage is applied, a very large (theoretically infinite) current can be generated, and a huge magnetic field and magnetic force can be obtained; or when the current passes through it, no voltage reduction and power loss occur. Obviously, its practical application will cause changes in human production and life, and has attracted great attention from people.
But for ordinary metals, superconductivity occurs only when the temperature drops very close to absolute zero (-273 °C), which is difficult to achieve in engineering. In recent years, some superconducting alloys have been developed with higher critical temperatures than those of pure metals. For example, Nb3Sn alloys are 18.1K.But their applications are not inseparable from copper at all。The first is that these alloys must work at ultra-low temperatures, which must be achieved through the liquefaction of gases. For example, the liquefaction temperatures of liquid helium, liquid hydrogen and liquid nitrogen are 4K(-269 ℃), 20K (-253 ℃) and 77K (-196 ℃) respectively.Copper still has good toughness and plasticity at such low temperatures and is an indispensable structural and pipeline transportation material in low-temperature engineering.In addition, superconducting alloys such as Nb3Sn and NbTi are very fragile and difficult to process into profiles, and copper needs to be used as a cladding material to combine them. At present, these superconducting materials have been used to make strong magnets, and have been used in nuclear magnetic resonance instruments for medical diagnosis and powerful magnetic separators in some mines. The maglev train under planning with a speed of more than 500 kilometers per hour will also rely on these superconducting material magnets to suspend the train to avoid the resistance of wheel-rail contact and achieve high-speed operation of the carriage.
※ Aerospace technology
In rockets, satellites and space shuttles, in addition to microelectronic control systems and instruments and instrumentation equipment, copper and copper alloys are also used in many key components. For example, the interior of the combustion chamber and thrust chamber of a rocket engine can be cooled using the excellent thermal conductivity of steel to keep the temperature within the allowable range. The combustion chamber of the Ariana 5 rocket uses copper-silver and combined gold. 360 cooling channels are processed in this village. Liquid hydrogen is introduced for cooling when the rocket is launched.
Also,Copper alloy is also a standard material for load-bearing members in satellite structures. Solar wings on satellites are usually made of alloys of copper and several other elements.
※ High-energy physics
Uncovering the mysteries of material structure is a major fundamental research topic that scientists strive to solve. Every step forward in our understanding of this issue can have significant impacts on humanity. The use of nuclear energy is a prime example of this. Recent advances in modern physics have revealed that the smallest units of matter are not molecules or atoms, but rather particles like quarks and leptons, which are hundreds of times smaller than those involved in atomic bomb explosions. Research into these fundamental particles often requires extremely high reaction energies, several hundred times higher than those produced during an atomic bomb explosion. This type of high-energy physics is conducted using particle accelerators, where charged particles are accelerated over long distances within strong magnetic fields before being directed at fixed targets. Alternatively, high-energy particles can be generated by collisions between two streams of particles moving in opposite directions. To achieve this, steel windings must be used to create long-distance magnetic field channels. Similarly, controlled thermonuclear reaction devices also require similar structures. To reduce the heat generated by large currents, these magnetic channels are made of hollow copper rods, allowing for the passage of cooling media to maintain proper temperature levels.
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Applications of copper compounds
Copper compounds mainly include: copper sulfate (pentahydrate, monohydrate and anhydrous), copper acetate, copper oxide and cuprous oxide, copper chloride and cuprous chloride, copper nitrate, copper cyanide, copper fatty acid, copper naphthenate, etc., are widely used in various fields such as agriculture, animal husbandry, industry, medical and health. Among them, the most widely used one is copper sulfate, usually copper sulfate pentahydrate (CuSO4·5H2O). Due to its blue color, it is commonly known as blue alum. It is often also a raw material for the production of many other salts.
The history of human application of steel compounds can be traced back to more than 5,000 years ago.It was found in the tomb that ancient Egyptians had used copper sulfate as a mordant (coloring agent) during dyeing, has been used to this day. According to statistics, there are currently more than 100 factories producing copper sulfate in the world, and the world's annual consumption is about 200,000 tons. It is estimated that 3/4 of this is used in agriculture and animal husbandry, mainly as a fungicide.
※ Application in agriculture and animal husbandry
Copper compounds are effective fungicides for eliminating pests and diseases, and can control all diseases caused by mold or fungi. In addition to the direct use of copper sulfate bubble seeds, some copper salt mixtures are often used in orchards and farmland. The most important are Bordeaux (lime copper sulfate) and Bergenti (soda copper sulfate) named after the famous grape producing areas in France, as well as Paris Green and Bactericide.
According to reports, copper fungicides can be used to control more than 300 types of diseases that commonly occur in over a hundred kinds of crops. These crops include:
- Various perennial fruit trees such as grapes, citrus, bananas, apples, pears, peaches, etc.;
- Cash crops such as coffee, rubber, cotton, and sugar beets;
- Wheat, rice, corn, barley, oats and other grains;
- Beans, tomatoes, potatoes, lettuce, etc.
Copper is an essential micronutrient for maintaining the healthy growth of crops and livestock. Generally, when the effective copper content in farmland soil falls below 2 ppmm (where 1 ppmm equals one percent), crops will suffer from reduced yields due to copper deficiency. In severe cases, crops may not be harvested at all. Similarly, when the effective copper content in pasture soil is below 5 ppmm, livestock can develop copper deficiency disorders. Currently, due to intensive high-yield farming practices, a large amount of fertilizers are used, but these fertilizers often contain very little or no copper. This leads to soil degradation, making copper deficiency an increasingly serious issue worldwide. To address this problem, it is necessary to supplement soils with copper salts promptly. Copper salts can be added directly or together with fertilizers rich in nitrogen and phosphorus. They can also be used to improve soil quality over time, or sprayed on crop seedlings every year. For livestock, in addition to improving pastures, copper salts can be mixed into feed, or other methods can be used to deliver copper to livestock that show signs of copper deficiency.Sodium sulfate is also a promoter for pigs and chickens, can increase their appetite and enhance food conversion. Mixing 0.1% copper sulfate in feed can significantly promote the weight gain of pigs and broilers.
Copper ions have a strong disinfection and sterilization effect and can prevent the epidemic of some common livestock diseases. For example, a small amount of copper (less than lppm) in water can eliminate water-growing mollusks such as mammals, snails and snails, which are hosts of schistosomiasis, thus preventing hepatic schistosomiasis, which is common in tropical and temperate animals. Copper sulfate can also be used to disinfect pens to prevent the rotten feet of cattle and sheep, as well as the spread of pig erysipelas and cow diarrhea.
In addition, the unpleasant green algae that contaminate ponds, rice fields, canals, and rivers can be removed by adding copper salts. Copper salts can serve as anti-mold and preservation agents, and are useful for storing grains, fruits, and vegetables. One simple way to do this is…Packaging with paper impregnated with copper salt。
※ Industrial applications
Copper compounds are widely used in industry, and they are used more or less in almost every industry. Here are some examples.
Copper sulfate is a commonly used dye in the printing and dyeing process to improve gloss persistence and washability. It is widely used in the textile and leather industries.
Copper compounds come in blue, green, red, black and other colors,It can be used as a colorant for glass, ceramics, cement, and enamel. They are also a component of certain hair dyes. Add copper nitrate to the fireworks to give off green light,Wait.
Paints that contain copper compounds have the ability to resist damage from marine organisms.
Some organic compounds of copper are effective preservatives and are used to preserve fabrics such as pulp, wood, woodwork and canvas.
Certain compounds of copper are important chemicals in the production of rubber, petroleum and artificial fibers, playing catalytic and purifying roles.
Copper sulfate electrolyte is used for copper plating, production of electrolytic copper foil and purification of copper.
In the mining industry, copper sulfate is used as an activator to float minerals such as lead, zinc, aluminum and gold.
※ Application in human health
Copper is an indispensable micronutrient for human health. It has an important impact on the development and function of the blood, central nervous system and immune system, hair, skin and bone tissue, as well as the brain, liver, heart and other internal organs. Copper is mainly consumed from daily diet. The World Health Organization recommends that in order to maintain health, adults should consume 0.03 milligrams of copper per kilogram of body weight per day. Pregnant women and infants should be doubled. Copper deficiency can lead to various diseases and can be supplemented with copper-containing supplements and pills.
Copper ions can be used for disinfection, sterilization, sanitation and epidemic prevention.For example, it can kill bacteria such as Escherichia coli and dysentery that easily breed in water, eliminate mollusks such as slugs and snails that transmit schistosomiasis in water, and disease carriers such as mosquito larvae that transmit malaria. It can also be used in swimming pools to prevent green algae contamination and the spread of tinea pedis through the floor.
Copper compounds can treat certain diseases.Sulphate has long been used to treat lung diseases and mental disorders in some Western countries; in some African and Asian countries, it is used to treat ulcers and skin diseases. Copper-containing drugs are currently under development.
