Copper is malleable and ductile and is a good conductor of both heat and electricity.
The purity of copper is expressed as 4N for 99.99% pure or 7N for 99.99999% pure. The numeral gives the number of nines after the decimal point when expressed as a decimal (e.g. 4N means 0.9999, or 99.99%). Copper is often too soft for its applications, so it is incorporated in numerous alloys. For example, brass is a copper-zinc alloy, and bronze is a copper-tin alloy.[40]
It is used extensively, in products such as:
Piping
- including water supply.
- used extensively in refrigeration and air conditioning equipment because of its ease of fabrication and soldering, as well as high conductivity to heat.
Electrical applications
- Copper wire
- Oxygen-free copper
- Electromagnets
- Printed circuit boards
- Lead free solder, alloyed with tin
- Electrical machines, especially electromagnetic motors, generators and transformers
- Electrical relays, electrical busbars and electrical switches
- Vacuum tubes, cathode ray tubes, and the magnetrons in microwave ovens
- Wave guides for microwave radiation
- Integrated circuits, increasingly replacing aluminium because of its superior electrical conductivity
- As a material in the manufacture of computer heat sinks, as a result of its superior heat dissipation capacity to aluminium
Architecture and industry
- While electrical applications use oxygen-free copper, unalloyed copper used in architectural applications is the lower-purty Phosphorus Deoxidized Copper (also called Cu-DHP).[41]
- Copper has been used as water-proof roofing material since ancient times, giving many old buildings their greenish roofs and domes. Initially copper oxide forms, replaced by cuprous and cupric sulfide, and finally by copper carbonate. The final carbonate patina (termed verdigris) is highly resistant to corrosion.[42]
- Statuary: The Statue of Liberty, for example, contains 179,220 pounds (81.29 metric tons) of copper.
- Alloyed with nickel, e.g. cupronickel and Monel, used as corrosive resistant materials in shipbuilding.
- Watt's steam engine firebox due to superior heat dissipation.
- Copper compounds in liquid form are used as a wood preservative, particularly in treating original portion of structures during restoration of damage due to dry rot.
- Copper wires may be placed over non-conductive roofing materials to discourage the growth of moss. (Zinc may also be used for this purpose.)
- Copper is used to prevent a building being directly struck by lightning. High above the roof, copper spikes (lightning rods) are connected to a very thick copper cable which leads to a large metal plate underneath the ground. The voltage is dispersed throughout the ground harmlessly, instead of destroying the main structure.[43]
Household products
- Copper plumbing fittings and compression tubes.
- Doorknobs and other fixtures in houses.
- Roofing, guttering, and rainspouts on buildings.
- In cookware, such as frying pans.
- Some older flatware: (knives, forks, spoons) contains some copper if made from electroplated nickel silver (EPNS).
- Sterling silver, if it is to be used in dinnerware, must contain a few percent copper.
- Copper water heating cylinders
- Copper range hoods
- Copper bath tubs
- Copper counters
- Copper sinks
- Copper slug tape
Coinage
- As a component of coins, often as cupronickel alloy, or some form of brass or bronze.[44]
- Coins in the following countries all contain copper: European Union (euro),[44] United States,[44][45] United Kingdom (sterling),[46] Australia[47] and New Zealand.[48]
- U.S. nickels are 75.0% copper by weight and only 25.0% nickel.[45]
Biomedical applications
- As a biostatic surface in hospitals, and to line parts of ships to protect against barnacles and mussels, originally used pure, but superseded by Muntz metal. Bacteria will not grow on a copper surface because it is biostatic. Copper doorknobs are used by hospitals to reduce the transfer of disease, and Legionnaires' disease is suppressed by copper tubing in air-conditioning systems.
- Copper(II) sulfate is used as a fungicide and as algae control in domestic lakes and ponds. It is used in gardening powders and sprays to kill mildew.
- Copper-62-PTSM, a complex containing radioactive copper-62, is used as a positron emission tomography radiotracer for heart blood flow measurements.
- Copper-64 can be used as a positron emission tomography radiotracer for medical imaging. When complexed with a chelate it can be used to treat cancer through radiation therapy.
Chemical applications
- Compounds, such as Fehling's solution, have applications in chemistry.
- As a component in ceramic glazes, and to color glass.
Miscellanea
- Musical instruments, especially brass instruments and timpani.
- Class D fire extinguisher, used in powder form to extinguish lithium fires by covering the burning metal and performing similar to a heat sink.
- Textile fibers to create antimicrobial protective fabrics.[49]
- Weaponry
- Small arms ammunition commonly uses copper as a jacketing material around the bullet core.
- Copper is also commonly used as a case material, in the form of brass.
- Copper is used as a liner in shaped charge armor-piercing warheads and demolition explosives (blade).
- Copper is frequently used in electroplating, usually as a base for other metals such as nickel.
Alloys
See also: List of copper alloys
Numerous copper alloys exist, many with important historical and contemporary uses. Speculum metal and bronze are alloys of copper and tin. Brass is an alloy of copper and zinc. Monel metal, also called cupronickel, is an alloy of copper and nickel. While the metal "bronze" usually refers to copper-tin alloys, it also is a generic term for any alloy of copper, such as aluminium bronze, silicon bronze, and manganese bronze. Copper is one of the most important constituents of carat silver and gold alloys and carat solders used in the jewelry industry, modifying the color, hardness and melting point of the resulting alloys.
No comments:
Post a Comment