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Brass is the term used for alloys of copper and zinc in a solid solution. It has a yellow color, somewhat similar to gold. It was produced in prehistoric times, long before zinc was discovered, by melting copper with calamine, a zinc ore.

The amount of zinc in brass varies from 5 to 45 percent, creating a range of brasses, each with unique properties.1 By comparison, bronze is principally an alloy of copper and tin.2 Despite this distinction, some types of brasses are called bronzes.

Brass is relatively resistant to tarnishing and is often used for decorative purposes. Its malleability and acoustic properties have made it the metal of choice for musical instruments such as the trombone, tuba, trumpet, and euphonium. Although saxophones and harmonicas are made out of brass, the saxophone is a woodwind instrument, and the harmonica, a free reed aerophone. In organ pipes designed as "reed" pipes, brass strips are used as the "reed."

Aluminum makes brass stronger and more corrosion-resistant. It forms a transparent, self-healing, protective layer of aluminum oxide (Al2O3) on the surface. Tin has a similar effect and finds its use especially in seawater applications (naval brasses). Combinations of iron, aluminum, silicon, and manganese make brass resistant to wear and tear.

Bronze

Assorted ancient bronze castings found as part of a cache.

Bronze refers to a broad range of copper alloys, usually with tin as the main additive, but sometimes with other elements such as phosphorus, manganese, aluminum, or silicon. Typically, bronze is about 60 percent copper and 40 percent tin.

The use of bronze was particularly significant for early civilizations, leading to the name "Bronze Age." Tools, weapons, armor, and building materials such as decorative tiles were made of bronze, as they were found to be harder and more durable than their stone and copper predecessors. In early use, the natural impurity arsenic sometimes created a superior natural alloy, called "arsenical bronze."

Though not as strong as steel, bronze is superior to iron in nearly every application. Bronze develops a patina (a green coating on the exposed surface), but it does not oxidize beyond the surface. It is considerably less brittle than iron and has a lower casting temperature. Several bronze alloys resist corrosion (especially by seawater) and metal fatigue better than steel; they also conduct heat and electricity better than most steels.

Bronze has myriad uses in industry. It is widely used today for springs, bearings, bushings, and similar fittings, and is particularly common in the bearings of small electric motors. It is also widely used for cast metal sculpture and is the most popular metal for top-quality bells and cymbals.

Commercial bronze, otherwise known as brass, is 90 percent copper and 10 percent zinc. It contains no tin.

Pewter

Pewter plate

Pewter is traditionally composed of 85 to 99 percent tin, with the remainder consisting of copper, which acts as a hardener. Lead is added to lower grades of pewter, giving a bluish tint.

Traditionally, there were three grades of pewter: fine, for eatingware, with 96 to 99 percent tin and 1 to 4 percent copper; trifle, also for eating and drinking utensils but duller in appearance, with 92 percent tin, 1 to 4 percent copper, and up to 4 percent lead; and lay or ley metal, not for eating or drinking utensils, which could contain up to 15 percent lead. Modern pewter mixes the tin with copper, antimony, and/or bismuth rather than lead.

Physically, pewter is a bright, shiny metal that is similar in appearance to silver. Like silver, it oxidizes to a dull gray over time if left untreated. It is a very malleable alloy, being soft enough to carve with hand tools. It also takes good impressions from punches or presses. Given this inherent softness and malleability, pewter cannot be used to make tools. Some types of pewter pieces, such as candlesticks, were turned on a metal lathe, and these items are sometimes referred to as "holloware." Pewter has a low melting point (around 225 to 240°C), depending on the exact mixture of metals. Duplication by casting gives excellent results.

The use of pewter was common from the Middle Ages up until the various developments in glass-making during the eighteenth and nineteenth centuries. Pewter was the chief tableware until the making of china. With the mass production of glass products, glass has universally replaced pewter in daily life. Today, pewter is mainly used for decorative objects such as collectible statuettes and figurines, replica coins, and pendants.

Nickel silver (German silver)

Nickel silver is an alloy of copper, nickel, and often (but not always) zinc. It is named for its silvery appearance and contains no elemental silver. Other common names for this alloy are German silver, paktong, new silver, and alpacca (or alpaca).

Many different formulations of alloys fall in the general category of "nickel silver." Besides containing copper, nickel, and zinc, some formulations may include antimony, tin, lead, or cadmium. A representative industrial formulation (Alloy No.752) is 65 percent copper, 18 percent nickel, and 17 percent zinc. In metallurgical science, such alloys would be more properly termed nickel bronze. Some nickel silver alloys, especially those containing high proportions of zinc, are stainless.

The earliest use of nickel silver appears to have been in China. It became known to the West from imported wares called Paktong or Pakfong, where the silvery metal color was used to imitate sterling silver. It was discovered to be an alloy composed of copper, nickel, and zinc in the eighteenth century.

Nickel silver first became popular as a base metal for silver-plated cutlery and other silverware, notably the electroplated wares called "E.P.N.S." (electro-plated nickel silver). It is used in zippers, costume jewelry, and musical instruments (such as cymbals). After about 1920, its use became widespread for pocketknife bolsters, due to its machinability and corrosion resistance. In some countries, it is used in the production of coins. Its industrial and technical uses include marine fittings and plumbing fixtures for its corrosion resistance, and heating coils for its high electrical resistance.

Steel

Main article: Steel

Steel is an alloy composed mainly of iron, with carbon content between 0.02 and 1.7 percent by weight. Carbon is the most cost-effective alloying material for iron, but many other alloying elements are also used.3 Carbon and other elements act as hardening agents, preventing iron atoms in the crystal lattice from sliding past one another.

By varying the amount of alloying elements and their distribution in the steel, one can control its qualities such as hardness, elasticity, ductility, and tensile strength. Steel with increased carbon content can be made harder and stronger than iron, but it is also more brittle. The maximum solubility of carbon in iron is 1.7 percent by weight, occurring at 1130 °C. Higher concentrations of carbon or lower temperatures produce cementite, which reduces the material's strength. Alloys with higher carbon content than this are known as cast iron because of their lower melting point. Steel should also be distinguished from wrought iron, with little or no carbon (usually less than 0.035 percent).

Currently, there are several classes of steels in which carbon is replaced with other alloying materials, and carbon, if present, is undesired. More recently, steels have been defined as iron-based alloys that can be plastically formed-pounded, rolled, and so forth.

List of alloys

This is a list of alloys grouped by the main metallic constituent, in order of increasing atomic number of the main metal. Under these headings, the alloys are in no particular order. Some of the main alloying elements are optionally listed after the alloy names.

Alloys of aluminum

  • Al-Li (lithium, mercury)
  • Duralumin (copper)
  • Nambe (seven undisclosed metals)
  • Magnox (magnesium oxide)
  • Zamak (zinc, magnesium, copper)
  • Silumin (silicon)

Alloys of potassium

  • NaK (sodium)

Alloys of iron

  • Steel (carbon)
    • Stainless steel (chromium, nickel)
      • AL-6XN
      • Alloy 20
      • Celestrium
      • Marine grade stainless
      • Martensitic stainless steel
      • Surgical stainless steel (chromium, molybdenum, nickel)
    • Silicon steel (silicon)
    • Tool steel (tungsten or manganese)
    • Bulat steel
    • Chromoly (chromium, molybdenum)
    • Crucible steel
    • Damascus steel
    • HSLA steel
    • High speed steel
    • Maraging steel
    • Reynolds 531
    • Wootz steel
  • Iron
    • Anthracite iron (carbon)
    • Cast iron (carbon)
    • Pig iron (carbon)
    • Wrought iron (carbon)
  • Fernico (nickel, cobalt)
  • Elinvar (nickel, chromium)
  • Invar (nickel)
  • Kovar (cobalt)
  • Spiegeleisen (manganese, carbon, silicon)
  • Ferroalloys
    • Ferroboron
    • Ferrochrome
    • Ferromagnesium
    • Ferromanganese
    • Ferromolybdenum
    • Ferronickel
    • Ferrophosphorus
    • Ferrotitanium
    • Ferrovanadium
    • Ferrosilicon

Alloys of cobalt

  • Megallium
  • Stellite (chromium, tungsten, carbon)
  • Talonite
  • Alnico
  • Vitallium

Alloys of nickel

  • Nickel silver / German silver (copper, zinc)
  • Chromel (chromium)
  • Hastelloy (molybdenum, chromium, sometimes tungsten)
  • Inconel (chromium, iron)
  • Mu-metal (iron)
  • Monel metal (copper, nickel, iron, manganese)
  • Nichrome (chromium, iron, nickel)
  • Nicrosil (chromium, silicon, magnesium)
  • Nisil (silicon)
  • Nitinol (titanium, shape memory alloy)
  • Copper-Nickel (bronze, copper)

Alloys of copper

  • Beryllium copper (beryllium)
  • Billon (silver)
  • Brass (zinc)
    • Calamine brass (zinc)
    • Chinese silver (zinc)
    • Gilding metal (zinc)
    • Muntz metal (zinc)
    • Pinchbeck (zinc)
    • Prince's metal (zinc)
    • Tombac (zinc)
  • Bronze (tin, aluminum, or any other element)
    • Aluminum bronze (aluminum)
    • Bell metal (tin)
    • Guanín
    • Gunmetal (tin, zinc)
    • Phosphor bronze (tin and phosphorus)
    • Ormolu (Gilt Bronze) (zinc)
    • Speculum metal (tin)
  • Constantan (nickel)
  • Corinthian brass (gold, silver)
  • Cunife (nickel, iron)
  • Cupronickel (nickel)
  • Cymbal alloys (Bell metal) (tin)
  • Devarda's alloy (aluminum, zinc)
  • Hepatizon (gold, silver)
  • Heusler alloy (manganese, tin)
  • Manganin (manganese, nickel)
  • Nickel silver (nickel)
  • Nordic gold (aluminum, zinc, tin)
  • Shakudo (gold)
  • Tumbaga (gold)

Alloys of gallium

  • Galinstan

Alloys of silver

  • Sterling silver (copper)
  • Britannia silver (copper)

Alloys of tin

  • Britannium (copper, antimony)4
  • Pewter (lead, copper)
  • Solder (lead, antimony)

Rare earth alloys

  • Mischmetal (various rare earths)

Alloys of gold

  • Corinthian brass (copper)
  • Electrum (silver, copper)
  • Tumbaga (copper)
  • Rose gold (copper)
  • White gold

Alloys of mercury

  • Amalgam

Alloys of lead

  • Solder (tin)
  • Terne (tin)
  • Type metal (tin, antimony)

Alloys of bismuth

  • Wood's metal
  • Rose metal
  • Field's metal
  • Cerrobend

Alloys of zirconium

  • Zircaloy

Related topics

Notes

  1. Engineering Designer 30, no. 3 (May-June 2004): 6-9.
  2. ↑ Erik Oberg, Machinery Handbook 24th Edition (New York: Industrial Press, 1991), 501.
  3. ↑ Michael F. Ashby and David R. Jones, Engineering Materials 2 (Pergamon Press, 1986 ISBN 0080325327).
  4. ↑ All About Oscar, Roll Out the Red Carpet, Teaching the News, March 18, 2002. Retrieved May 25, 2007.

References

  • Bodsworth, Colin, and Henry Bradley Bell. 1972. Physical Chemistry of Iron and Steel Manufacture. London: Longman. ISBN 0582441161.
  • Davis, J.R. (editor) (2001). ASM Specialty Handbook: Copper and Copper Alloys. ASM International. ISBN 0871707268.
  • Maynard, H.B. (2005). Brass and Alloy Founding. Lindsay Publications. ISBN 1559183160.
  • Tylecote, R. F. 1992. A History of Metallurgy. London: Institute of Materials. ISBN 0901462888.
  • Whyman, Kathryn, Louise Nevett, and Simon Bishop. 1988. Metals and Alloys. Resources Today. New York: Gloucester Press. ISBN 0531170837.
  • Woldman, Norman Emme, and Robert C. Gibbons. 1973. Engineering Alloys. New York: Van Nostrand Reinhold. ISBN 0442226691.

External links

All links retrieved March 8, 2016.

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