Ferrous and Non Ferrous Metals

MANUFACTURING PROCESS

MANUFACTURING PROCESS PROJECT

TOPIC - NON FERROUS AND FERROUS METALS

Submitted By :- Submitted To :-KARAN GARG VIKAS KUMAR SINGLA

Roll no: 100903045Group-: 1CO3INTRODUCTIONMethod of classifying metals is by their content, and one common division is into ferrous metals and non-ferrous metals. The term ferrous is derived from the Latin "Ferrum" which means "containing iron", thus ferrous metals contain iron and non ferrous metals do not. Ferrous metals may be pure iron, like wrought iron, or they may be alloys of iron and other elements. Steel, being an alloy of iron and carbon, would therefore be a ferrous metal.

Ferrous metals are often magnetic, but this property is not in and of itself sufficient to classify a metal as ferrous or non-ferrous. Austenitic stainless steel, a ferrous metal, is non-magnetic, while cobalt is magnetic but non-ferrous. However since ferrous metals are the most common magnetic materials, magnets are commonly used to separate them from non-ferrous metals and other materials.

Common ferrous metals include the various irons and steels. Common non-ferrous metals include aluminium, tin, copper, zinc, and brass, an alloy of copper and zinc. The precious metals silver, gold, and platinum are also non-ferrous.

NON FERROUS METALS. Copper (Cu)

Aluminium (AL)

Zinc (Zn) Tin (Sn)COPPER ::-

Copper is a chemical element in the periodic table that has the symbol Cu (Latin: cuprum) and atomic number 29. It is a ductile metal with excellent electrical conductivity, and finds extensive use as an electrical conductor, thermal conductor, as a building material, and as a component of various alloys.

Copper is an essential nutrient to all higher plants and animals. In animals, it is found primarily in the bloodstream, as a cofactor in various enzymes, and in copper-based pigments. In sufficient amounts, copper can be poisonous or even fatal to organisms.

Copper has played a significant part in the history of mankind, which has used the easily accessible uncompounded metal for nearly 10,000 years. Civilizations in places like Iraq, China, Egypt, Greece and the Sumerian cities all have early evidence of using copper, and Britain and the United States also have extensive histories of copper use and mining. During the Roman Empire, copper was principally mined on Cyprus, hence the origin of the name of the metal as Cyprium, "metal of Cyprus", later shortened to Cuprum. A number of countries, such as Chile and the United States, still have sizeable reserves of the metal which are extracted through large open mines.

General Properties

Name, Symbol, Numbercopper, Cu, 29

Chemical seriestransition metals

Group, Period, Block11, 4, d

Appearancemetallic pinkish red

Atomic mass63.546

HYPERLINK "http://en.wikipedia.org/wiki/List_of_elements_by_atomic_mass" \o "List of elements by atomic mass" (3) gmol1

Electron configuration[Ar] 3d10 4s1

Electrons per shell2, 8, 18, 1

Physical properties

Phasesolid

Density (near r.t.)8.96 gcm3

Liquid density at m.p.8.02 gcm3

Melting point1357.77K(1084.62C, 1984.32F)

Boiling point2835K(2562C, 4643F)

Heat of fusion13.26 kJmol1

Heat of vaporization300.4 kJmol1

Heat capacity(25C) 24.440 Jmol1K1

Vapor pressureP(Pa)

1

10

100

1 k

10 k

100 k

at T(K)

1509

1661

1850

2089

2404

2836

Atomic properties

Crystal structureface centered cubic

Oxidation states2, 1(mildly basic oxide)

Electronegativity1.90 (Pauling scale)

Ionization energies(more)1st: 745.5 kJmol1

2nd: 1957.9 kJmol1

3rd: 3555 kJmol1

Atomic radius135 pm

Atomic radius (calc.)145 pm

Covalent radius138 pm

Van der Waals radius140 pm

Miscellaneous

Magnetic orderingparamagnetic

Electrical resistivity(20C) 16.78 nm

Thermal conductivity(300K) 401 Wm1K1

Thermal expansion(25C) 16.5 mm1K1

Speed of sound (thin rod)(r.t.) (annealed)3810 ms1

Young's modulus130 Gpa

Shear modulus48 Gpa

Bulk modulus140 Gpa

Poisson ratio0.34

Mohs hardness3.0

Vickers hardness369 Mpa

Brinell hardness874 Mpa

CAS registry number7440-50-8

Selected isotopes

Main article: Isotopes of copperisoNAhalf-lifeDMDE (MeV)

DP63Cu

69.17%

Cu is stable with 34 neutrons65Cu

30.83%

Cu is stable with 36 neutrons

Notable characteristics

Copper just above its melting point keeps its pink luster color when enough light overshines the orange incandescence color.

Copper is a reddish-colored metal, with a high electrical and thermal conductivity (silver is the only pure metal to have a higher electrical conductivity at room temperature).[1] In oxidation copper is mildly basic. Copper has its characteristic color because it reflects red and orange light and absorbs other frequencies in the visible spectrum, due to its band structure. This can be contrasted with the optical properties of silver, gold and aluminium.

Copper occupies the same family of the periodic table as silver and gold, since they each have one S-orbital electron on top of a filled shell. This similarity in electron structure makes them similar in many characteristics. All have very high thermal and electrical conductivity, and all are malleable metals.

In its liquid state, a clear copper surface without ambient light appears somewhat greenish, another characteristic shared with gold. Silver does not have this property, so it is not a complementary color for the orange incandescence color. When liquid copper is in bright ambient light, it retains some of its pinkish luster. Due to its high surface tension, the liquid metal does not wetten surfaces but instead forms spherical droplets when poured on a surface.

Copper is insoluble in water (H2O) as well as in isopropanol.

There are two stable isotopes, 63Cu and 65Cu, along with a couple dozen radioisotopes. The vast majority of radioisotopes have half lives on the order of minutes or less; the longest lived, 64Cu, has a half life of 12.7 hours, with two decay modes leading to two separate products.

Numerous alloys of copper 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.

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 (eg 4N means 0.9999, or 99.99%).

Applications

Copper is malleable and ductile, a good conductor of heat and, when very pure, a good conductor of electricity.

It is used extensively, in products such as:

Electronics:Copper wire.

Electromagnets.

Printed circuit boards.

Electrical machines, especially electromagnetic motors and generators.

Electrical relays, electrical busbars and electrical switches.

Vacuum tubes, cathode ray tubes, and the magnetrons in microwave ovens.

Wave guides for microwave radiation.

Structural Engineering:Statuary: The Statue of Liberty, for example, contains 179,200 pounds (81.3 tonnes) of copper.

Alloyed with nickel, e.g. cupronickel and Monel, used as corrosive resistant materials in shipbuilding.

Watt's steam engine.

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.

Most flatware (knives, forks, spoons) contains some copper (nickel silver).

Sterling silver, if it is to be used in dinnerware, must contain a few percent copper.

Copper was sometimes used by the Inuit to make the cutting blade for ulus.

Copper water heating cylinders

Coinage:As a component of coins, often as cupronickel alloy.

Euro coins contain different copper alloys

Since 1982, U.S. Pennies are 0.8% copper by weight (Balance zinc 99.2%).

U.S. Nickels are 75.0% copper by weight (Balance nickel 25.0%).

Since 1965, U.S. Dimes and Quarters are 91.67% copper by weight (Balance nickel 8.33%).

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.

Chemical applications:Catalysis:

Compounds, such as Fehling's solution, have applications in chemistry.

As a component in ceramic glazes, and to color glass.

Used in the Water gas shift reaction which converts carbon monoxide into carbon dioxide.

Steam reforming which extracts hydrogen from hydrocarbons.

Others:Musical instruments, especially brass instruments and cymbals.HistoryThe Egyptians found that adding a small amount of tin made the metal easier to cast, so bronze alloys were found in Egypt almost as soon as copper was found. Copper is found extensively in the Indus Valley Civilization by the 3rd millennium BC[2]. By 1200 BC excellent bronzes were being made in China. Note that these dates are affected by wars and conquest, as copper is easily melted down and reused. In Europe, Oetzi the Iceman, a well-preserved male dated to 3200 BC, was found with a copper-tipped axe whose metal was 99.7% pure.

There are copper and bronze artifacts from Sumerian cities that date to 3000 BC, and Egyptian artifacts of copper and copper-tin alloys nearly as old. In one pyramid, a copper plumbing system was found that is 5000 years old. In the Americas production in the Old Copper Complex, located in present day Michigan and Wisconsin, was dated back to at least 6000 to 3000 BC.[3]In Greek times, the metal was known by the name chalkos (). Copper was a very important resource for the Romans and Greeks. In Roman times, it became known as aes Cyprium (aes being the generic Latin term for copper alloys such as bronze and other metals, and Cyprium because so much of it was mined in Cyprus).

Ancient Copper ingot from Zakros, Crete is shaped in the form of an animal skin typical for that era.

The use of bronze was so pervasive in a certain era of civilization that it has been named the Bronze Age. The transitional period in certain regions between the preceding Neolithic period and the Bronze Age is termed the Chalcolithic, with some high-purity copper tools being used alongside stone tools.

Copper mining in Britain and the United States Copper has been mined for many centuries. By 2000 BC, Europe was using copper-tin alloys or bronze. The Bronze Age is taken as 2500 BC to 600 BC.

West Mine at Alderley Edge

British Isles

During the Bronze age, copper was mined in the British Isles mainly in the following locations:

South West County CorkWest Wales (e.g. Cwmwystwyth)

North Wales (e.g. Great Orme)

Anglesey (Parys Mountain)

Cheshire (Alderley Edge)

The Staffordshire Moorlands (e.g. Ecton Mine)

Isle of Man, which is between England and Northern Ireland

At Great Orme in North Wales, such working extended for a depth of 70 metres.[5] At Alderley Edge in Cheshire, carbon dates have established mining at around 2280 - 1890 BC (at 95% probability).[6]United States

Miners at the Tamarack Mine in Copper Country, Michigan, USA in 1905.

Copper mining in United States began with marginal workings by Native Americans and some development by early Spaniards. Europeans were mining copper in Connecticut as early as 1709. Westward movement also brought an expansion of copper exploitation with developments of significant deposits in Michigan and Arizona during the 1850's and then in Montana during the 1860's.

Copper was mined extensively in Michigan's Keweenaw Peninsula with the heart of extraction at the productive Quincy Mine. Arizona had many notable deposits including the Copper Queen in Bisbee and the United Verde in Jerome. The Anaconda in Butte, Montana became the nation's chief copper supplier by 1886.

Copper has also been made in Utah, Nevada and Tennessee, and among other locations.

Biological role

Copper is essential in all higher plants and animals. Copper is carried mostly in the bloodstream on a plasma protein called ceruloplasmin. When copper is first absorbed in the gut it is transported to the liver bound to albumin. Copper is found in a variety of enzymes, including the copper centers of cytochrome c oxidase and the enzyme superoxide dismutase (containing copper and zinc). In addition to its enzymatic roles, copper is used for biological electron transport. The blue copper proteins that participate in electron transport include azurin and plastocyanin. The name "blue copper" comes from their intense blue color arising from a ligand-to-metal charge transfer (LMCT) absorption band around 600 nm.

Most molluscs and some arthropods such as the horseshoe crab use the copper-containing pigment hemocyanin rather than iron-containing hemoglobin for oxygen transport, so their blood is blue when oxygenated rather than red.[7]It is believed that zinc and copper compete for absorption in the digestive tract so that a diet that is excessive in one of these minerals may result in a deficiency in the other. The RDA for copper in normal healthy adults is 0.9 mg/day.

Toxicity

All copper compounds, unless otherwise known, should be treated as if they were toxic. Thirty grams of copper sulfate is potentially lethal in humans. The suggested safe level of copper in drinking water for humans varies depending on the source, but tends to be pegged at 1.5 to 2 mg/L. The DRI Tolerable Upper Intake Level for adults of dietary copper from all sources is 10 mg/day. In toxicity, copper can inhibit the enzyme dihydrophil hydratase, an enzyme involved in haemopoiesis.

Symptoms of copper poisoning are very similar to those produced by arsenic. Coppery eructations and taste. Fatal cases are generally terminated by convulsions, palsy, and insensibility.

In cases of suspected copper poisoning, albumen is to be administered in either of its forms which can be most readily obtained, as milk or whites of eggs. Vinegar should not be given. The inflammatory symptoms are to be treated on general principles, and so of the nervous.

Too much copper in water has also been found to damage marine life. The observed effect of these higher concentrations on fish and other creatures is damage to gills, liver, kidneys, and the nervous system.

Miscellaneous hazards

The metal, when powdered, is a fire hazard. At concentrations higher than 1 mg/L, copper can stain clothes and items washed in water.

Occurrence

Chuquicamata (Chile). The largest open pit copper mine in the world.

The main copper ore producing countries are Chile, United States, Indonesia, Australia, Peru, Russia, Canada, China, Poland, Kazakhstan, Zambia and Mexico.[9]Copper can be found as native copper in mineral form. Minerals such as the sulfides: chalcopyrite (CuFeS2), bornite (Cu5FeS4), covellite (CuS), chalcocite (Cu2S) are sources of copper, as are the carbonates: azurite (Cu3(CO3)2(OH)2) and malachite (Cu2CO3(OH)2) and the oxide: cuprite (Cu2O).

Most copper ore is mined or extracted as copper sulfides from large open pit mines in porphyry copper deposits that contain 0.4 to 1.0 percent copper. Examples include: Chuquicamata in Chile and El Chino Mine in New Mexico. The average abundance of copper found within crustal rocks is approximately 68 ppm by mass, and 22 ppm by atoms.

Native Copper Placer Nuggets

Native copper

The Intergovernmental Council of Copper Exporting Countries (CIPEC), defunct since 1992, once tried to play a similar role for copper as OPEC does for oil, but never achieved the same influence, not least because the second-largest producer, the United States, was never a member. Formed in 1967, its principal members were Chile, Peru, Zaire, and Zambia.

The copper price has quintupled since 1999, rising from $0.60 per pound in June 1999 to $3.75 per pound in May 2006 where it began to drop steadily, most recently dropping below $3.00 per pound in December of 2006[1].

Compounds

Common oxidation states of copper include the less stable copper(I) state, Cu+; and the more stable copper(II) state, Cu2+, which forms blue or blue-green salts and solutions. Under unusual conditions, a 3+ state and even an extremely rare 4+ state can be obtained.

Copper(II) carbonate is green from which arises the unique appearance of copper-clad roofs or domes on some buildings. Copper(II) sulfate forms a blue crystalline pentahydrate which is perhaps the most familiar copper compound in the laboratory. It is used as a fungicide, known as Bordeaux mixture.

There are two stable copper oxides, copper(II) oxide (CuO) and copper(I) oxide (Cu2O). Copper oxides are used to make yttrium barium copper oxide (YBa2Cu3O7-) or YBCO which forms the basis of many unconventional superconductors.

Copper (I) compounds: copper(I) chloride, copper(I) bromide, copper(I) iodide, copper(I) oxide.

Copper (II) compounds: copper(II) carbonate, copper(II) chloride, copper(II) hydroxide, copper(II) nitrate, copper(II) oxide, copper(II) sulfate, copper(II) sulfide.

Copper (III) compounds , rare: potassium hexafluorocuprate (K3CuF6)

Copper (IV) compounds , extremely rare: caesium hexafluorocuprate (Cs2CuF6)

Copper (I) and Copper (II) can also be referred to by their common names cuprous and cupric.

Tests for copper(II) ion

Add aqueous sodium hydroxide. A blue precipitate of copper(II) hydroxide should form.

Ionic equation:

Cu2+(aq) + 2OH(aq) Cu(OH)2(s)

The full equation shows that the reaction is due to hydroxide ions deprotonating the hexaaquacopper (II) complex:

[Cu(H2O)6]2+(aq) + 2 OH(aq) Cu(H2O)4(OH)2(s) + 2 H2O (l)

Adding aqueous ammonia causes the same precipitate to form. It then dissolves upon adding excess ammonia, to form a deep blue ammonia complex, tetraamminecopper(II).

Ionic equation:

Cu(H2O)4(OH)2(s) + 4 NH3(aq) [Cu(H2O)2(NH3)4]2+(aq) + 4 H2O (l)

A more delicate test than the ammonia is the ferrocyanide of potassium, which gives a brown precipitate with copper salts.

Alloys of copper Classification of Copper and Its Alloys

FamilyPrincipal alloying elementUNS numbers

Copper alloys, BrassZinc (Zn)C1xxxxC4xxxx,C66400C69800

Phosphor bronzesTin (Sn)C5xxxx

Aluminium bronzesAluminium (Al)C60600C64200

Silicon bronzesSilicon (Si)C64700C66100

Copper nickel, Nickel silversNickel (Ni)C7xxxx

Brasses

A brass is an alloy of copper with zinc. Brasses are usually yellow in color. The zinc content can vary between few % to about 40%; as long as it is kept under 15%, it does not markedly decrease corrosion resistance of copper.

Brasses can be sensitive to selective leaching corrosion under certain conditions, when zinc is leached from the alloy (dezincification), leaving behind a spongy copper structure.

Bronzes

A bronze is an alloy of copper and other metals, most often tin, but also aluminium and silicon.

Aluminium bronzes are alloys of copper and aluminium. The content of aluminium ranges mostly between 5-11%. Iron, nickel, manganese and silicon are sometimes added. They have higher strength and corrosion resistance than other bronzes, especially in marine environment, and have low reactivity to sulfur compounds. Aluminium forms a thin passivation layer on the surface of the metal.

Phosphor bronzeNickel bronzes, eg. nickel silver and cupronickelPrecious metal alloys

Copper is often alloyed with precious metals like silver and gold, to create, for example, Corinthian bronze, hepatizon, tumbaga and shakudo.

ALUMINIUM ::--

13magnesium aluminium silicon

BAlGa

Periodic Table - Extended Periodic Table

General properties

Name, Symbol, Numberaluminium, Al, 13

Chemical seriespoor metals

Group, Period, Block13, 3, p

Appearancesilvery

Atomic mass26.9815386


Electron configuration[Ne] 3s2 3p1

Electrons per shell2, 8, 3

Physical properties

Phasesolid








Vapor pressureP(Pa)

1

10

100

1 k

10 k

100 k

at T(K)

1482

1632

1817

2054

2364

2790

Atomic properties

Crystal structureface centered cubic,0.4032 nm

Oxidation states3(amphoteric oxide)



2nd: 1816.7 kJmol1

3rd: 2744.8 kJmol1

Atomic radius125 pm



Miscellaneous

Magnetic orderingparamagnetic




Speed of sound (thin rod)(r.t.) (rolled) 5000 ms1

Young's modulus70 Gpa

Shear modulus26 Gpa

Bulk modulus76 Gpa

Poisson ratio0.35

Mohs hardness2.75

Vickers hardness167 Mpa

Brinell hardness245 Mpa


Selected isotopes

Main article: Isotopes of aluminiumisoNAhalf-lifeDMDE (MeV)

DP26Al

syn7.17105

HYPERLINK "http://en.wikipedia.org/wiki/Year" \o "Year" y+1.17

26Mg-

26Mg1.8086

-

27Al

100%

Al is stable with 14 neutrons

Aluminium is found primarily and is remarkable for its ability to resist corrosion (due to the phenomenon of passivation) and its light weight. The metal is used in many industries to manufacture a large variety of products and is very important to the world economy. Structural components made from aluminium and its alloys are vital to the aerospace industry and very important in other areas of transportation and building.PropertiesAluminium is a soft, lightweight metal with normally a dull silvery appearance caused by a thin layer of oxidation that forms quickly when the metal is exposed to air. Aluminium oxide has a higher melting point than pure aluminium. Aluminium is nontoxic (as the metal), nonmagnetic, and nonsparking. It has a tensile strength of about 49 megapascals (MPa) in a pure state and 400 MPa as an alloy.

Aluminium is one of the few metals which retains full silvery reflectance, even in finely powdered form, which makes it a very important component of silver paints.

Aluminium mirror finish has the highest reflectance of any metal in the 200-400 nm (UV) and the 3000-10000 nm (far IR) regions, while in the 400-700 nm visible range it is slightly outdone by silver and in the 700-3000 (near IR) by silver, gold, and copper. It is the second-most malleable metal (after gold) and the sixth-most ductile. Aluminium is a good thermal and electrical conductor. Aluminium is capable of being a superconductor, with a superconducting critical temperature of 1.2 Kelvin.

Applications

As the metal

A piece of aluminium metal about 15 centimetres long, with a U.S. cent included for scale.

Whether measured in terms of quantity or value, the global use of aluminium exceeds that of any other metal except iron, and it is important in virtually all segments of the world economy.

Relatively pure aluminium is encountered only when corrosion resistance and/or workability is more important than strength or hardness. Pure aluminium serves as an excellent reflector (approximately 99%) of visible light and a good reflector (approximately 95%) of infrared. A thin layer of aluminium can be deposited onto a flat surface by chemical vapor deposition or chemical means to form optical coatings and mirrors. These coatings form an even thinner layer of protective aluminium oxide that does not deteriorate, as silver coatings do. Nearly all modern mirrors are made using a thin coating of aluminium on the back surface of a sheet of float glass.

Pure aluminium has a low tensile strength, but when combined with thermo-mechanical processing, aluminium alloys display a marked improvement in mechanical properties. Aluminium alloys form vital components of aircraft and rockets as a result of their high strength-to-weight ratio. Aluminium readily forms alloys with many elements such as copper, zinc, magnesium, manganese and silicon (e.g., duralumin).

Some of the many uses for aluminium metal are in:

Transportation (automobiles, aircraft, trucks, railroad cars, marine vessels, bicycles etc.)

Packaging (cans, foil, etc.)

Water treatmentTreatment against fish parasites such as Gyrodactylus salaris.

Construction (windows, doors, siding, building wire, etc.)

Consumer durable goods (appliances, cooking utensils, etc.)

Electrical transmission lines (aluminium components and wires are less dense than those made of copper and are lower in price[1], but also present higher electrical resistance. Many localities prohibit the use of aluminium in residential wiring practices because of its higher resistance and thermal expansion value.)

Machinery

MKM steel and Alnico magnets, although non-magnetic itself

Super purity aluminium (SPA, 99.980% to 99.999% Al), used in electronics and CDs.

Powdered aluminium, a commonly used silvering agent in paint, due to its retention of reflectance, even as powder. Aluminium flakes may also be included in undercoat paints, particularly wood primer on drying, the flakes overlap to produce a water resistant barrier.

Anodised aluminium is more stable to further oxidation, and is used in various fields of construction, as well as heat sinking.

Aluminium Compounds

Aluminium fluorosilicate (Al2(SiF6)3) is used in the production of synthetic gemstones, glass and ceramics.

Aluminium ammonium sulfate (Al(NH4)(SO4)2) is used: as a mordant, in water purification and sewage treatment, in paper production, as a food additive, and in leather tanning.

Aluminium borate (Al2O3 B2O3) is used in the production of glass and ceramics.

Aluminium borohydride (Al(BH4)3) is used as an additive in jet fuels.

Aluminium chloride (AlCl3) is used: in paint manufacturing, in antiperspirants, in petroleum refining and in the production of synthetic rubber.

Aluminium hydroxide (Al(OH)3) is used: as an antacid, as a mordant, in water purification, in the manufacture of glass and ceramics and in the waterproofing of fabrics.

Aluminium oxide (Al2O3, alumina, is found naturally as corundum (rubies and sapphires), emery, and is used in glass making. Synthetic ruby and sapphire are used in lasers for the production of coherent light. Aluminium oxidises very energetically and as a result has found use in solid rocket fuels, thermite, and other pyrotechnic compositions.

Aluminium phosphate (AlPO4) is used in the manufacture: of glass and ceramics, pulp and paper products, cosmetics, paints and varnishes and in making dental cement.

Aluminium sulphate (Al2(SO4)3) is used: in the manufacture of paper, as a mordant, in a fire extinguisher, in water purification and sewage treatment, as a food additive, in fireproofing, and in leather tanning.

In many vaccines, certain aluminium salts serve as an immune adjuvant (immune response booster) to allow the protein in the vaccine to achieve succicient potency as an immune stimulant.

Engineering use

Aluminium alloys with a wide range of properties are used in engineering structures. Alloy systems are classified by a number system (ANSI) or by names indicating their main alloying constituents (DIN and ISO). Selecting the right alloy for a given application entails considerations of strength, ductility, formability, weldability and corrosion resistance to name a few. A brief historical overview of alloys and manufacturing technologies is given in Ref.[2] Aluminium is used extensively in modern aircraft due to its high strength to weight ratio.

Where failure is not an issue but excessive flex is undesirable due to requirements for precision of location, or efficiency of transmission of power, simple replacement of steel tubing with similarly sized aluminium tubing will result in a degree of flex which is undesirable; for instance, the increased flex under operating loads caused by replacing steel bicycle frame tubing with aluminium tubing of identical dimensions will cause misalignment of the power-train as well as absorbing the operating force. To increase the rigidity by increasing the thickness of the walls of the tubing increases the weight proportionately, so that the advantages of lighter weight are lost as the rigidity is restored.

In such cases, aluminium may best be used by redesigning the dimension of the part to suit its characteristics; for instance making a bicycle frame of aluminium tubing which has an oversize diameter rather than thicker walls. In this way, rigidity can be restored or even enhanced without increasing weight.[3] The limit to this process is the increase in susceptibility to what is termed "buckling" failure, where the deviation of the force from any direction other than directly along the axis of the tubing, causes folding of the walls of the tubing.

The latest models of the Corvette automobile, among others, are a good example of redesigning parts to make best use of aluminium's advantages. The aluminium chassis members and suspension parts of these cars have large overall dimensions for stiffness but are lightened by reducing cross-sectional area and removing unneeded metal; as a result, they are not only equally or more durable and stiff as the usual steel parts, but they possess an airy gracefulness which most people find attractive. Similarly, aluminium bicycle frames can be optimally designed so as to provide rigidity where required, yet exhibit some extra flexibility which functions as a natural shock-absorber for the rider.

The strength and durability of aluminium varies widely, not only as a result of the components of the specific alloy, but also as a result of the particular manufacturing process. This variability, plus a learning-curve in employing it, has from time to time gained aluminium a bad reputation. For instance, a high frequency of failure in many poorly-designed early aluminium bicycle frames in the 1970s, temporarily hurt aluminum's reputation for this use. However, the widespread use of aluminium components in the aerospace and automotive high performance industries, where huge stresses are withstood with vanishingly small failure rates, illustrates that properly-built aluminium bicycle components need not be intrinsically unreliable. Time and experience has subsequently proven this to be the case.

One important structural limitation of an aluminium alloy is its fatigue properities. While steel has a high fatigue limit (the structure can theoretically withstand an infinite number of cyclical loadings at this stress), aluminium's fatigue limit is near zero, meaning that it will eventually fail under even very small cyclic loadings.

Heat sensitivity

Often, the metal's sensitivity to heat must also be considered. Even a relatively routine workshop procedure involving heating is complicated by the fact that aluminium, unlike steel, will melt without first glowing red. Forming operations where a blow torch is used therefore requires some expertise, since no visual signs reveal how close the material is to melting.

Aluminium also is subject to internal stresses and strains when it is overheated; the tendency of the metal to creep under these stresses tends to result in delayed distortions. For instance, the warping or cracking of overheated aluminium automobile cylinder heads is commonly observed, sometimes years later, as is the tendency of welded aluminium bicycle frames to gradually twist out of alignment from the stresses of the welding process. Thus, the aerospace industry avoids heat altogether by joining parts with adhesives or mechanical fasteners. Adhesive bonding was used in some bicycle frames in the 1970s, with unfortunate results when the aluminium tubing corroded slightly, loosening the adhesive and collapsing the frame.

Stresses in overheated aluminium can be relieved by heat-treating the parts in an oven and gradually cooling it in effect annealing the stresses. Yet these parts may still become distorted, so that heat-treating of welded bicycle frames, for instance, can result in a significant fraction becoming misaligned. If the misalignment is not too severe, the cooled parts may be bent into alignment. Of course, if the frame is properly designed for rigidity (see above), that bending will require enormous force.

Aluminium's intolerance to high temperatures has not precluded its use in rocketry; even for use in constructing combustion chambers where gases can reach 3500 K. The Agena upper stage engine used a regeneratively cooled aluminium design for some parts of the nozzle, including the thermally critical throat region; in fact the extremely high thermal conductivity of aluminium prevented the throat from reaching the melting point even under massive heat flux, resulting in a reliable lightweight component.Household wiringBecause of its high conductivity and relatively low price compared to copper in the 1960s, aluminium was introduced at that time for household electrical wiring in the United States, even though many fixtures had not been designed to accept aluminium wire. But the new use brought some problems:

The greater coefficient of thermal expansion of aluminium causes the wire to expand and contract relative to the dissimilar metal screw connection, eventually loosening the connection.

Pure aluminium has a tendency to "creep" under steady sustained pressure (to a greater degree as the temperature rises), again loosening the connection.

Galvanic corrosion from the dissimilar metals increases the electrical resistance of the connection.

All of this resulted in overheated and loose connections, and this in turn resulted in some fires. Builders then became wary of using the wire, and many jurisdictions outlawed its use in very small sizes, in new construction. Yet newer fixtures eventually were introduced with connections designed to avoid loosening and overheating. At first they were marked "Al/Cu", but they now bear a "CO/ALR" coding.

Another way to forestall the heating problem is to crimp the aluminium wire to a short "pigtail" of copper wire. A properly done high-pressure crimp by the proper tool is tight enough to reduce any thermal expansion of the aluminium. Today, new alloys, designs, and methods are used for aluminium wiring in combination with aluminium terminations.

History

The ancient Greeks and Romans used aluminium salts as dyeing mordants and as astringents for dressing wounds; alum is still used as a styptic. In 1761 Guyton de Morveau suggested calling the base alum alumine. In 1808, Humphry Davy identified the existence of a metal base of alum, which he at first named alumium and later aluminum (see Spelling section, below).

Friedrich Whler is generally credited with isolating aluminium (Latin alumen, alum) in 1827 by mixing anhydrous aluminium chloride with potassium. The metal, however, had indeed been produced for the first time two years earlier but in an impure form by the Danish physicist and chemist Hans Christian rsted. Therefore, rsted can also be listed as the discoverer of the metal.[4] Further, Pierre Berthier discovered aluminium in bauxite ore and successfully extracted it. [3] The Frenchman Henri Saint-Claire Deville improved Whler's method in 1846 and described his improvements in a book in 1859, chief among these being the substitution of sodium for the considerably more expensive potassium.

The statue known as Eros in Piccadilly Circus London, was made in 1893 and is one of the first statues to be cast in aluminium.

Aluminium was selected as the material to be used for the apex of the Washington Monument, at a time when one ounce cost twice the daily wages of a common worker in the project; aluminium was a semiprecious metal at that time.[5]The American Charles Martin Hall of Oberlin, Ohio applied for a patent (400655) in 1886 for an electrolytic process to extract aluminium using the same technique that was independently being developed by the Frenchman Paul Hroult in Europe. The invention of the Hall-Hroult process in 1886 made extracting aluminium from minerals cheaper, and is now the principal method in common use throughout the world. The Hall-Heroult process cannot produce Super Purity Aluminium directly. Upon approval of his patent in 1889, Hall, with the financial backing of Alfred E. Hunt of Pittsburgh, PA, started the Pittsburgh Reduction Company, renamed to Aluminum Company of America in 1907, later shortened to Alcoa.

Germany became the world leader in aluminium production soon after Adolf Hitler's rise to power. By 1942, however, new hydroelectric power projects such as the Grand Coulee Dam gave the United States something Nazi Germany could not hope to compete with, namely the capability of producing enough aluminium to manufacture sixty thousand warplanes in four years.[6]Aluminium metal production and refinement

Although aluminium is the most abundant metallic element in Earth's crust (believed to be 7.5% to 8.1%), it is very rare in its free form, occurring in oxygen-deficient environments such as volcanic mud, and it was once considered a precious metal more valuable than gold. Napoleon III, Emperor of the French, is reputed to have given a banquet where the most honoured guests were given aluminium utensils, while the other guests had to make do with gold ones [7]

HYPERLINK "http://en.wikipedia.org/wiki/Aluminium" \l "_note-2#_note-2" \o "" [8]. Aluminium has been produced in commercial quantities for just over 100 years. [citations needed]Aluminium is a reactive metal that is difficult to extract from ore, aluminium oxide (Al2O3). Direct reduction with carbon, for example is not economically viable since aluminium oxide has a melting point of about 2,000 C. Therefore, it is extracted by electrolysis; that is, the aluminium oxide is dissolved in molten cryolite and then reduced to the pure metal. By this process, the operational temperature of the reduction cells is around 950 to 980 C. Cryolite is found as a mineral in Greenland, but in industrial use it has been replaced by a synthetic substance. Cryolite is a mixture of aluminium, sodium, and calcium fluorides: (Na3AlF6). The aluminium oxide (a white powder) is obtained by refining bauxite in the Bayer process. (Previously, the Deville process was the predominant refining technology.)

The electrolytic process replaced the Whler process, which involved the reduction of anhydrous aluminium chloride with potassium. Both of the electrodes used in the electrolysis of aluminium oxide are carbon. Once the ore is in the molten state, its ions are free to move around. The reaction at the cathode the negative terminal isAl3+ + 3 e- Al

Here the aluminium ion is being reduced (electrons are added). The aluminium metal then sinks to the bottom and is tapped off.

At the positive electrode (anode), oxygen is formed:

2 O2- O2 + 4 e-This carbon anode is then oxidised by the oxygen, releasing carbon dioxide. The anodes in a reduction must therefore be replaced regularly, since they are consumed in the process:

O2 + C CO2Unlike the anodes, the cathodes are not oxidised because there is no oxygen present at the cathode. The carbon cathode is protected by the liquid aluminium inside the cells. Nevertheless, cathodes do erode, mainly due to electrochemical processes. After five to ten years, depending on the current used in the electrolysis, a cell has to be rebuilt because of cathode wear.

Aluminium electrolysis with the Hall-Hroult process consumes a lot of energy, but alternative processes were always found to be less viable economically and/or ecologically. The world-wide average specific energy consumption is approximately 150.5 kilowatt-hours per kilogram of aluminium produced from alumina. (52 to 56 MJ/kg). The most modern smelters reach approximately 12.8 kWh/kg (46.1 MJ/kg). Reduction line current for older technologies are typically 100 to 200 kA. State-of-the-art smelters operate with about 350 kA. Trials have been reported with 500 kA cells.

Electric power represents about 20% to 40% of the cost of producing aluminium, depending on the location of the smelter. Smelters tend to be situated where electric power is both plentiful and inexpensive, such as South Africa, the South Island of New Zealand, Australia, the People's Republic of China, the Middle East, Russia, Quebec and British Columbia in Canada, and Iceland.

In 2004, the People's Republic of China was the top world producer of aluminium.

Isotopes

Aluminium has nine isotopes, whose mass numbers range from 23 to 30. Only 27Al (stable isotope) and 26Al (radioactive isotope, t1/2 = 7.2 105 y) occur naturally, however 27Al has a natural abundance of 100%. 26Al is produced from argon in the atmosphere by spallation caused by cosmic-ray protons. Aluminium isotopes have found practical application in dating marine sediments, manganese nodules, glacial ice, quartz in rock exposures, and meteorites. The ratio of 26Al to 10Be has been used to study the role of transport, deposition, sediment storage, burial times, and erosion on 105 to 106 year time scales.[citation needed]Cosmogenic 26Al was first applied in studies of the Moon and meteorites. Meteorite fragments, after departure from their parent bodies, are exposed to intense cosmic-ray bombardment during their travel through space, causing substantial 26Al production. After falling to Earth, atmospheric shielding protects the meteorite fragments from further 26Al production, and its decay can then be used to determine the meteorite's terrestrial age. Meteorite research has also shown that 26Al was relatively abundant at the time of formation of our planetary system. Possibly, the energy released by the decay of 26Al was responsible for the remelting and differentiation of some asteroids after their formation 4.6 billion years ago.[citation needed]Clusters

In the journal Science of 14 January 2005 it was reported that clusters of 13 aluminium atoms (Al13) had been made to behave like an iodine atom; and, 14 aluminium atoms (Al14) behaved like an alkaline earth atom. The researchers also bound 12 iodine atoms to an Al13 cluster to form a new class of polyiodide. This discovery is reported to give rise to the possibility of a new characterisation of the periodic table: superatoms. The research teams were led by Shiv N. Khanna (Virginia Commonwealth University) and A. Welford Castleman Jr (Penn State University).[10]Precautions

Aluminium is a neurotoxin that alters the function of the blood-brain barrier.[11] It is one of the few abundant elements that appears to have no beneficial function to living cells. A small percent of people are allergic to it they experience contact dermatitis from any form of it: an itchy rash from using styptic or antiperspirant products, digestive disorders and inability to absorb nutrients from eating food cooked in aluminium pans, and vomiting and other symptoms of poisoning from ingesting such products as Rolaids, Amphojel, and Maalox (antacids). In other people, aluminium is not considered as toxic as heavy metals, but there is evidence of some toxicity if it is consumed in excessive amounts. The use of aluminium cookware, popular because of its corrosion resistance and good heat conduction, has not been shown to lead to aluminium toxicity in general. Excessive consumption of antacids containing aluminium compounds and excessive use of aluminium-containing antiperspirants are more likely causes of toxicity. In research published in the Journal of Applied Toxicology, Dr. Philippa D. Darby of the University of Reading has shown that aluminium salts increase estrogen-related gene expression in human breast cancer cells grown in the laboratory. These salts' estrogen-like effects have lead to their classification as a metalloestrogen.

It has been suggested that aluminium is a cause of Alzheimer's disease, as some brain plaques have been found to contain the metal. Research in this area has been inconclusive; aluminium accumulation may be a consequence of the Alzheimer's damage, not the cause. In any event, if there is any toxicity of aluminium it must be via a very specific mechanism, since total human exposure to the element in the form of naturally occurring clay in soil and dust is enormously large over a lifetime.[12],[13]Mercury applied to the surface of an aluminium alloy can damage the protective oxide surface film. This may cause further corrosion and weakening of the structure. For this reason, mercury thermometers are not allowed on many airliners, as aluminium is used in many aircraft structures.

Powdered aluminium can react with Fe2O3 to form Fe and Al2O3. This mixture is known as thermite, which burns with a high energy output. Thermite can be produced inadvertently during grinding operations, but the high ignition temperature makes incidents unlikely in most workshop environments.

Aluminium and plants (Phytoremediation)

Aluminium is primary among the factors that contribute to the loss of plant production on acid soils. Although it is generally harmless to plant growth in pH-neutral soils, the concentration in acid soils of toxic Al3+ cations increases and disturbs root growth and function.

Wheat's adaptation to allow aluminium tolerance is such that the aluminium induces a release of organic compounds that bind to the harmful aluminium cations. Sorghum is believed to have the same tolerance mechanism. The first gene for aluminium tolerance has been identified in wheat. A group in the US Department of Agriculture showed that sorghum's aluminium tolerance is controlled by a single gene, as for wheat. This is not the case in all plants.

ChemistryOxidation state one

AlH is produced when aluminium is heated at 1500C in an atmosphere of hydrogen.

Al2O is made by heating the normal oxide, Al2O3, with silicon at 1800C in a vacuum.

Al2S can be made by heating Al2S3 with aluminium shavings at 1300C in a vacuum. It quickly disproportionates to the starting materials. The selenide is made in a parallel manner.

AlF, AlCl and AlBr exist in the gaseous phase when the tri-halide is heated with aluminium.

Oxidation state two

Aluminium monoxide, AlO, is present when aluminium powder burns in oxygen.

Oxidation state three

Fajans rules show that the simple trivalent cation Al3+ is not expected to be found in anhydrous salts or binary compounds such as Al2O3. The hydroxide is a weak base and aluminium salts of weak acids, such as carbonate, can't be prepared. The salts of strong acids, such as nitrate, are stable and soluble in water, forming hydrates with at least six molecules of water of crystallization.

Aluminium hydride, (AlH3)n, can be produced from trimethylaluminium and an excess of hydrogen. It burns explosively in air. It can also be prepared by the action of aluminium chloride on lithium hydride in ether solution, but cannot be isolated free from the solvent.

Aluminium carbide, Al4C3 is made by heating a mixture of the elements above 1000C. The pale yellow crystals have a complex lattice structure, and react with water or dilute acids to give methane. The acetylide, Al2(C2)3, is made by passing acetylene over heated aluminium.

Aluminium nitride, AlN, can be made from the elements at 800C. It is hydrolysed by water to form ammonia and aluminium hydroxide.

Aluminium phosphide, AlP, is made similarly, and hydrolyses to give phosphine.

Aluminium oxide, Al2O3, occurs naturally as corundum, and can be made by burning aluminium in oxygen or by heating the hydroxide, nitrate or sulfate. As a gemstone, its hardness is only exceeded by diamond, boron nitride, and carborundum. It is almost insoluble in water.

Aluminium hydroxide may be prepared as a gelatinous precipitate by adding ammonia to an aqueous solution of an aluminium salt. It is amphoteric, being both a very weak acid, and forming aluminates with alkalis. It exists in various crystalline forms.

Aluminium sulfide, Al2S3, may be prepared by passing hydrogen sulfide over aluminium powder. It is polymorphic.

Aluminium iodide, (AlI3)2, is a dimer with applications in organic synthesis.

Aluminium fluoride, AlF3, is made by treating the hydroxide with HF, or can be made from the elements. It consists of a giant molecule which sublimes without melting at 1291C. It is very inert. The other trihalides are dimeric, having a bridge-like structure.

Aluminium fluoride/water complexes: When aluminium and fluoride are together in aqueous solution, they readily form complex ions such as AlF(H2O)5+2, AlF3(H2O)30, AlF6-3. Of these, AlF6-3 is the most stable. This is explained by the fact that aluminium and fluoride, which are both very compact ions, fit together just right to form the octahedral aluminium hexafluoride complex. When aluminium and fluoride are together in water in a 1:6 molar ratio, AlF6-3 is the most common form, even in rather low concentrations.

ALLOYS OF ALUMINIUM Al-Li (lithium)

Duralumin (copper)

Nambe (aluminium plus seven other undisclosed metals)

Silumin (silicon)

AA-8000: used for building wire in the U.S. per the National Electrical Code Magnalium (5% magnesium)/used in airplane bodies, ladders,etc.

Aluminium also forms complex metallic alloys, like -Al-Mg, '-Al-Pd-Mn, T-Al3Mn

ZINC::-

General Properties

Name, Symbol, Numberzinc, Zn, 30

Chemical seriestransition metals

Group, Period, Block12, 4, d

Appearancebluish pale gray

Atomic mass65.409


Electron configuration[Ar] 3d10 4s2

Electrons per shell2, 8, 18, 2

Physical properties

Phasesolid








Vapor pressureP(Pa)

1

10

100

1 k

10 k

100 k

at T(K)

610

670

750

852

990

(1185)

Atomic properties

Crystal structureHexagonal

Oxidation states2(amphoteric oxide)



2nd: 1733.3 kJmol1

3rd: 3833 kJmol1

Atomic radius135 pm




Miscellaneous

Magnetic orderingdiamagnetic





Young's modulus108 GPa

Shear modulus43 GPa

Bulk modulus70 GPa

Poisson ratio0.25

Mohs hardness2.5

Brinell hardness412 MPa


Selected isotopes

Main article: Isotopes of zincisoNAhalf-lifeDMDE (MeV)

DP64Zn

48.6%

Zn is stable with 34 neutrons65Zn

syn244.26 d-

65Cu1.1155

-

66Zn

27.9%


4.1%


18.8%


syn56.4 min

0.906

69Ga70Zn

0.6%

Zn is stable with 40 neutrons

Zinc is a chemical element in the periodic table that has the symbol Zn and atomic number 30.


Zinc is a moderately-reactive bluish-white metal that tarnishes in moist air and burns in air with a bright greenish flame, giving off plumes of zinc oxide. It reacts with acids, alkalis and other non-metals. If not completely pure, zinc reacts with dilute acids to release hydrogen. The one common oxidation state of zinc is +2. From 100 C to 210 C zinc metal is malleable and can easily be beaten into various shapes. Above 210 C, the metal becomes brittle and will be pulverized by beating.

Applications

Zinc is the fourth most common metal in use, trailing only iron, aluminium, and copper in annual production.

Zinc is used to galvanize steel to prevent corrosion.

Zinc is used to Parkerize steel to prevent rust and corrosion

Zinc is used in alloys such as brass, nickelled silver, typewriter metal, various soldering formulas and German silver.

Zinc is the primary metal used in making American cents since 1982.

Zinc is used in die casting notably in the automobile industry.

Zinc is used as part of the containers of batteries. The most widespread such use is as the anode in alkaline batteries.

Zinc is used as the anode or fuel of the zinc-air battery/fuel cell providing the basis of the theorised zinc economy.

Zinc is used as a sacrificial anode on boats and ships that use cathodic protection to prevent corrosion of metals that are exposed to sea water.Zinc is used in contemporary pipe organ building as a substitute for the classic lead/tin alloy in pipes sounding the lowest (pedal) tones, as it is tonally almost indistinguishable from lead/tin at those pitches, and has the added advantages of being much more economical and lighter in weight. Even the best organ builders use zinc in this capacity.

Zinc oxide is used as a white pigment in watercolours or paints, and as an activator in the rubber industry. As an over-the-counter ointment, it is applied as a thin coating on the exposed skin of the face or nose to prevent dehydration of the area of skin. It can protect against sunburn in the summer and windburn in the winter. Applied thinly to a baby's diaper area (perineum) with each diaper change, it can protect against rash. As determined in the Age-Related Eye Disease Study, it is part of an effective treatment for age-related macular degeneration in some cases.

Zinc chloride is used as a deodorant and can also be used as a wood preservative.

Zinc sulfide is used in luminescent pigments such as on the hands of clocks and other items that glow in the dark.

Zinc methyl (Zn(CH3)2) is used in a number of organic syntheses.

Zinc stearate is a lubricative plastic additive.

Lotions made of calamine, a mix of Zn-(hydroxy-)carbonates and silicates, are used to treat skin rash.

Zinc gluconate glycine and zinc acetate are also used in throat lozenges or tablets in an attempt to remedy the common cold. [1]History

Zinc

In ancient India the production of zinc metal was very common. Many mine sites of Zawarmaala were active even during 1300-1000 BC. There are references of medicinal uses of zinc in the Charaka Samhita (300 BC). The Rasaratna Samuccaya (800 AD) explains the existence of two types of ores for zinc metal, one of which is ideal for metal extraction while the other is used for medicinal purpose. [2] Zinc alloys have been used for centuries, as brass goods dating to 10001400 BC have been found in Israel and zinc objects with 87% zinc have been found in prehistoric Transylvania. Because of the low boiling point and high chemical reactivity of this metal (isolated zinc would tend to go up the chimney rather than be captured), the true nature of this metal was not understood in ancient times.

The manufacture of brass was known to the Romans by about 30 BC, using a technique where calamine and copper were heated together in a crucible. The zinc oxides in calamine were reduced, and the free zinc metal was trapped by the copper, forming an alloy. The resulting calamine brass was either cast or hammered into shape.

Smelting and extraction of impure forms of zinc was accomplished as early as 1000 AD in India and China. In the West, impure zinc as a remnant in melting ovens was known since Antiquity, but usually discarded as worthless. Strabo mentions it as pseudo-arguros "mock silver". The Berne zinc tablet is a votive plaque dating to Roman Gaul, probably made from such zinc remnants. The discovery of pure metallic zinc is most often credited to the German Andreas Marggraf, in the year 1746, though the whole story is disputed.[citation needed]The English metallurgist Libavius received in 1597 a quantity of zinc metal in its pure form, which was unknown in the West before then. Libavius identified it as Indian/Malabar lead. Paracelsus (1616) was credited with the name "zinc". Postlewayt's Universal Dictionary, the most authentic source of all technological information in Europe, did not mention zinc before 1751.

In 1738, William Champion is credited with patenting in Britain a process to extract zinc from calamine in a smelter, a technology he acquired after visiting Zawar zinc mines in Rajasthan. His first patent was rejected by the patent court on grounds of plagiarising the technology common in India. However he was granted the patent on his second submission of patent approval.

Before the discovery of the zinc sulfide flotation technique, calamine was the mineral source of zinc metal.

Foods and spices that contain the essential mineral zinc

Biological role

Zinc is an essential element, necessary for sustaining all life. It is estimated that 3000 of the hundreds of thousands of proteins in the human body contain zinc prosthetic groups.[citation needed] In addition, there are over a dozen types of cells in the human body that secrete zinc ions, and the roles of these secreted zinc signals in medicine and health are now being actively studied. Intriguingly, brain cells in the mammalian forebrain are one type of cell that secretes zinc, along with its other neuronal messenger substances. Cells in the salivary gland, prostate, immune system and intestine are other types that secrete zinc.[citation needed]Zinc is an activator of certain enzymes, such as carbonic anhydrase. Carbonic anhydrase is important in the transport of carbon dioxide in vertebrate blood. It is also required in plants for leaf formation, the synthesis of indole acetic acid (auxin) and anaerobic respiration (alcoholic fermentation).[citation needed]Food sources

Zinc is found in oysters, and to a far lesser degree in most animal proteins, beans, nuts, whole grains, pumpkin seeds and sunflower seeds. Phytates, which are found in whole grain breads, cereals, legumes and other products, have been known to decrease zinc absorption. Clinical studies have found that zinc, combined with antioxidants, may delay progression of age-related macular degeneration[citation needed], but the effect is extremely small and not likely to be clinically important. Significant dietary intake of zinc has also recently been shown to impede the onset of flu[citation needed]. Soil conservation analyzes the vegetative uptake of naturally occurring zinc in many soil types.

Zinc deficiency

Zinc deficiency results from inadequate intake of zinc, or inadequate absorption of zinc into the body. Signs of zinc deficiency includes hair loss, skin lesions, diarrhea, wasting of body tissues, and, eventually, death. Eyesight, taste, smell and memory are also connected with zinc. A deficiency in zinc can cause malfunctions of these organs and functions. Congenital abnormalities causing zinc deficiency may lead to a disease called Acrodermatitis enteropathica.

Obtaining a sufficient zinc intake during pregnancy and in young children is a very real problem, especially among those who cannot afford a good and varied diet. Brain development is stunted by zinc insufficiency in utero and in youth.Zinc toxicityEven though zinc is an essential requirement for a healthy body, too much zinc can be harmful. Excessive absorption of zinc can also suppress copper and iron absorption. The free zinc ion in solution is highly toxic to plants, invertebrates, and even vertebrate fish. The Free Ion Activity Model (FIAM) is well-established in the literature, and shows that just micromolar amounts of the free ion kills some organisms. A recent example showed 6 micromolar killing 93% of all daphnia in water. [3] Swallowing an American one cent piece (98% zinc) can also cause damage to the stomach lining due to the high solubility of the zinc ion in the acidic stomach. [4] Zinc toxicity, mostly in the form of the ingestion of US pennies minted after 1982, is commonly fatal in dogs where it causes a severe hemolytic anemia.

Immune system

Zinc salts are effective against pathogens in direct application. Gastrointestinal infections are also strongly attenuated by ingestion of zinc, and this effect could be due to direct antimicrobial action of the zinc ions in the GI tract, or to absorption of the zinc and re-release from immune cells (all granulocytes secrete zinc) or both.

The direct effect of zinc (as in lozenges) on bacteria and viruses is also well-established, and has been used since at least 2000 BC, from when zinc salts in palliative salves are documented. However, exactly how to deliver zinc salts against pathogens without injuring one's own tissues is still being investigated.

Abundance

Zinc is the 23rd most abundant element in the Earth's crust. The most heavily mined ores (sphalerite) tend to contain roughly 10% iron as well as 4050% zinc. Minerals from which zinc is extracted include sphalerite (zinc sulfide), smithsonite (zinc carbonate), hemimorphite (zinc silicate), and franklinite (a zinc spinel).

Zinc mining and processing

There are zinc mines throughout the world, with the largest producers being Australia, Canada, China, Peru and the U.S.A. Mines and refiners in Europe include Umicore in Belgium, Tara, Galmoy and Lisheen in Ireland, and Zinkgruvan in Sweden. Zinc metal is produced using extractive metallurgy. Zinc sulfide (sphalerite) minerals are concentrated using the froth flotation method and then usually roasted using pyrometallurgy to oxidise the zinc sulfide to zinc oxide. The zinc oxide is leached in several stages of increasingly stronger sulfuric acid (H2SO4). Iron is usually rejected as Jarosite or goethite, removing other impurities at the same time. The final purification uses zinc dust to remove copper, cadmium and cobalt. The metal is then extracted from the solution by electrowinning as cathodic deposits. Zinc cathodes can be directly cast or alloyed with aluminium.There are two common processes for electrowinning the metal, the low current density process, and the Tainton high current density process. The former uses a 10% sulfuric acid solution as the electolyte, with current density of 270325 amperes per square meter. The latter uses 22-28% sulfuric acid solution as the electrolyte with current density of about 1000 amperes per square meter.

There are also several pyrometallurgical processes that reduce zinc oxide using carbon, then distill the metallic zinc from the resulting mix in an atmosphere of carbon monoxide. These include the Belgian-type horizontal-retort process, the New Jersey Zinc continuous vertical-retort process, and the St. Joseph Lead Company's electrothermal process. The Belgian process requires redistillation to remove impurities of lead, cadmium, iron, copper, and arsenic.

Another pyrometallurgical process is flash smelting. Then zinc oxide is obtained, usually producing zinc of lesser quality than the hydrometallurgical process. Zinc oxide treatment has much fewer applications, but high grade deposits have been successful in producing zinc from zinc oxides and zinc carbonates using hydrometallurgy.

Alloys

The most widely used alloy of zinc is brass, in which copper is alloyed with anywhere from 9% to 45% zinc, depending upon the type of brass, along with much smaller amounts of lead and tin. Alloys of 8588% zinc, 410% copper, and 28% aluminum find limited use in certain types of machine bearings. Alloys of primarily zinc with small amounts of copper, aluminum, and magnesium are useful in die-casting. Similar alloys with the addition of a small amount of lead can be cold-rolled into sheets. An alloy of 96% zinc and 4% aluminum is used to make stamping dies for low production run applications where ferrous metal dies would be too expensive.Compounds

Zinc oxide is perhaps the best known and most widely used zinc compound, as it makes a good base for white pigments in paint. It also finds industrial use in the rubber industry, and is sold as opaque sunscreen. A variety of other zinc compounds find use industrially, such as zinc chloride (in deodorants), zinc pyrithione (anti-dandruff shampoos), zinc sulfide (in luminescent paints), and zinc methyl or zinc diethyl in the organic laboratory. Roughly one quarter of all zinc output is consumed in the form of zinc compounds.

Isotopes

Naturally occurring zinc is composed of the 5 stable isotopes 64Zn, 66Zn, 67Zn, 68Zn, and 70Zn with 64Zn being the most abundant (48.6% natural abundance). Twenty-one radioisotopes have been characterised with the most abundant and stable being 65Zn with a half-life of 244.26 days, and 72Zn with a half-life of 46.5 hours. All of the remaining radioactive isotopes have half-lives that are less than 14 hours and the majority of these have half lives that are less than 1 second. This element also has 4 meta states.

Zinc has been proposed as a "salting" material for nuclear weapons (cobalt is another, better-known salting material). A jacket of isotopically enriched 64Zn, irradiated by the intense high-energy neutron flux from an exploding thermonuclear weapon, would transmute into the radioactive isotope Zn-65 with a half-life of 244 days and produce approximately 2.27 MeV of gamma radiation, significantly increasing the radioactivity of the weapon's fallout for several days. Such a weapon is not known to have ever been built, tested, or used.

Precautions

Metallic zinc is not considered to be toxic, but free zinc ions in solution (like copper or iron ions) are highly toxic. There is also a condition called zinc shakes or zinc chills (see metal fume fever) that can be induced by the inhalation of freshly formed zinc oxide formed during the welding of galvanized materials. Excessive intake of zinc can promote deficiency in other dietary minerals.

TIN::-

50indium tin antimonyGeSnPb

Periodic Table - Extended Periodic Table

General properties

Name, Symbol, Numbertin, Sn, 50

Chemical seriespoor metals

Group, Period, Block14, 5, p

Appearancesilvery lustrous gray

Atomic mass118.710


Electron configuration[Kr] 4d10 5s2 5p2

Electrons per shell2, 8, 18, 18, 4

Physical properties

Phasesolid

Density (near r.t.)(white) 7.265 gcm3

Density (near r.t.)(gray) 5.769 gcm3




Heat of fusion(white) 7.03 kJmol1

Heat of vaporization(white) 296.1 kJmol1

Heat capacity(25C) (white)27.112 Jmol1K1

Vapor pressureP(Pa)

1

10

100

1 k

10 k

100 k

at T(K)

1497

1657

1855

2107

2438

2893

Atomic properties

Crystal structureTetragonal

Oxidation states4, 2(amphoteric oxide)



2nd: 1411.8 kJmol1

3rd: 2943.0 kJmol1

Atomic radius145 pm




Miscellaneous

Magnetic orderingno data

Electrical resistivity(0 C) 115 nm

Thermal conductivity(300K) 66.8 Wm1K1



Young's modulus50 GPa

Shear modulus18 GPa

Bulk modulus58 GPa

Poisson ratio0.36

Mohs hardness1.5

Brinell hardness


Selected isotopes

Main article: Isotopes of tinisoNAhalf-lifeDMDE (MeV)

DP112Sn

0.97%

Sn is stable with 62 neutrons114Sn

0.65%


0.34%


14.54%


7.68%


24.23%


8.59%


32.59%


4.63%


5.79%


syn~1 E5 yBeta-0.380

126Sb

Tin chemical element in the periodic table that has the symbol Sn (Latin: stannum) and atomic number 50. This silvery, malleable poor metal that is not easily oxidized in air and resists corrosion, is found in many alloys and is used to coat other metals to prevent corrosion. Tin is obtained chiefly from the mineral cassiterite, where it occurs as an oxide.


Tin is a malleable, ductile, highly crystalline, silvery-white metal; when a bar of tin is bent, a strange crackling sound known as the "tin cry" can be heard due to the breaking of the crystals. This metal resists corrosion from distilled, sea and soft tap water, but can be attacked by strong acids, alkalis, and by acid salts. Tin acts as a catalyst when oxygen is in solution and helps accelerate chemical attack.

Tin forms the dioxide SnO2 when it is heated in the presence of air. SnO2, in turn, is feebly acidic and forms stannate (SnO3-2) salts with basic oxides. Tin can be highly polished and is used as a protective coat for other metals in order to prevent corrosion or other chemical action. This metal combines directly with chlorine and oxygen and displaces hydrogen from dilute acids. Tin is malleable at ordinary temperatures but is brittle when it is heated.

Allotropes

Chemically tin shows properties intermediate between those of metals and non-metals, just as the semiconductors silicon and germanium do. Tin has two allotropes at normal pressure and temperature, gray tin, and white tin.

Below 13.2 C it exists as gray or alpha tin, which has a cubic crystal structure similar to silicon and germanium. Gray tin has no metallic properties at all, is a dull-gray powdery material, and has no known uses.

When warmed above 13.2 C tin changes into white or beta tin, which is metallic and has a tetragonal structure. Converting gray tin powder into white tin produces white tin powder. To convert powdery gray tin into solid white tin the temperature must be raised above the melting point of tin.

Gray tin can be a real problem, since metallic white tin will slowly convert to gray tin if it is held for a long time below 13.2 Celsius. The metallic surface of white tin becomes covered with a gray powder which is easily rubbed off. The gray patches slowly expand until all of the tin in the object is converted from the metal to the powder, at which point it totally loses its structural integrity and falls to pieces. This process is known as tin disease or tin pest.

Applications

Tin bonds readily to iron, and has been used for coating lead or zinc and steel to prevent corrosion. Tin-plated steel containers are widely used for food preservation, and this forms a large part of the market for metallic tin. Speakers of British English call them "tins"; Americans call them "cans" or "tin cans". One thus-derived use of the slang term "tinnie" or "tinny" means "can of beer". The tin whistle is so called because it was first mass-produced in tin-plated steel.

Other uses:

Some important tin alloys are: bronze, bell metal, Babbitt metal, die casting alloy, pewter, phosphor bronze, soft solder, and White metal.

The most important salt formed is stannous chloride, which has found use as a reducing agent and as a mordant in the calico printing process. Electrically conductive coatings are produced when tin salts are sprayed onto glass. These coatings have been used in panel lighting and in the production of frost-free windshields.

Most metal pipes in a pipe organ are made of varying amounts of a tin/lead alloy, with 50%/50% being the most common. The amount of tin in the pipe defines the pipe's tone, since tin is the most tonally resonant of all metals. When a tin/lead alloy cools, the lead cools slightly faster and makes a mottled or spotted effect. This metal alloy is referred to as spotted metal.

Window glass is most often made via floating molten glass on top of molten tin (creating float glass) in order to make a flat surface (this is called the "Pilkington process").

Tin is also used in solders for joining pipes or electric circuits, in bearing alloys, in glass-making, and in a wide range of tin chemical applications. Although of higher melting point than a lead-tin alloy, the use of pure tin or tin alloyed with other metals in these applications is rapidly supplanting the use of the previously common leadcontaining alloys in order to eliminate the problems of toxicity caused by lead.

Tin foil was once a common wrapping material for foods and drugs; replaced in the early 20th century by the use of aluminium foil, which is now commonly referred to as tin foil. Hence one use of the slang term "tinnie" or "tinny" for a small retail package of a drug such as cannabis or for a can of beer.

Tin becomes a superconductor below 3.72 K. In fact, tin was one of the first superconductors to be studied; the Meissner effect, one of the characteristic features of superconductors, was first discovered in superconducting tin crystals.

History

Tin (Old English: tin, Old Latin: plumbum candidum, Old German: tsin, Late Latin: stannum) is one of the earliest metals known and was used as a component of bronze from antiquity. Because of its hardening effect on copper, tin was used in bronze implements as early as 3,500 BC. Tin mining is believed to have started in Cornwall and Devon (esp. Dartmoor) in Classical times, and a thriving tin trade developed with the civilizations of the Mediterranean[1]

HYPERLINK "http://en.wikipedia.org/wiki/Tin" \l "_note-1#_note-1" \o "" [2]. However the lone metal was not used until about 600 BC. The last Cornish Tin Mine, at South Crofty near Camborne closed in 1998 bringing 4000 years of mining in Cornwall to an end.

The word "tin" has cognates in many Germanic and Celtic languages. The American Heritage Dictionary speculates that the word was borrowed from a pre-Indo-European language. The later name of "stannum" and its Romance derivatures come from the lead-silver alloy of the same name for the winning of the latter in ores; its former "stagnum" was the word for a stale pool or puddel.

In modern times, the word "tin" is often (improperly) used as a generic phrase for any silvery metal that comes in thin sheets. Most everyday objects that are commonly called tin, such as aluminum foil, beverage cans, and tin cans, are actually made of steel or aluminum, although tin cans (tinned cans) do contain a thin coating of tin to inhibit rust. Likewise, so-called "tin toys" are usually made of steel, and may or may not have a thin coating of tin to inhibit rust.

Occurrence

About 35 countries mine tin throughout the world. Nearly every continent has an important tin-mining country. Tin is produced by reducing the ore with coal in a reverberatory furnace. This metal is a relatively scarce element with an abundance in the Earth's crust of about 2 ppm, compared with 94 ppm for zinc, 63 ppm for copper, and 12 ppm for lead. Most of the world's tin is produced from placer deposits; at least one-half comes from Southeast Asia. The only mineral of commercial importance as a source of tin is cassiterite (SnO2), although small quantities of tin are recovered from complex sulfides such as stannite, cylindrite, franckeite, canfieldite, and teallite. Secondary, or scrap, tin is also an important source of the metal.

Tasmania hosts some important deposits of historical importance, most importantly Mount Bischoff and Renison Bell.

see also Category:Tin mineralsIsotopes

Tin is the element with the greatest number of stable isotopes (ten), which is probably related to the fact that 50 is a "magic number" of protons. 28 additional unstable isotopes are known, including the "doubly magic" tin-100 (100Sn) (discovered in 1994)[3].

Compounds

For discussion of Stannate compounds (SnO32-) see Stannate. For Stannite (SnO2-) see Stannite. See also Stannous hydroxide (Sn(OH)2), Stannic acid (Stannic Hydroxide - Sn(OH)4), Tin dioxide (Stannic Oxide - SnO2), Tin(II) oxide (Stannous Oxide - SnO), Tin(II) chloride (SnCl2), Tin(IV) chloride (SnCl4)

see also category:Tin compoundsBiologic effects of organic tin compounds

The small amount of tin that is found in canned foods is not harmful to humans. Certain organic tin compounds, organotin, such as triorganotins (see tributyltin oxide) are toxic and are used as industrial fungicides and bactericides.

Alloys of tin Britannium (copper, antimony)

Pewter (lead, copper)

Solder (lead, antimony)

FERROUS METALS............

CARBON STEEL

ALOY STEEL

STAINLESS STEEL

TOOL STEEL

HSLA STEEL

STEELS FOR STRENGTH

Carbon Steel::-

Carbon steel, also called plain carbon steel, is a malleable, iron-based metal containing carbon, small amounts of manganese, and other elements that are inherently present. Steels can either be cast to shape or wrought into various mill forms from which finished parts are formed, machined, forged, stamped, or otherwise shaped.

Cast steels are poured to near-final shape in sand molds. The castings are then heat treated to achieve specified properties and machined to required dimensions.

Wrought steel undergoes two operations. First, it is either poured into ingots or strand cast. Then, the metal is reheated and hot rolled into the finished, wrought form. Hot-rolled steel is characterized by a scaled surface and a decarburized skin. Hot-rolled bars may be subsequently finished in a two-part process. First, acid pickling or shot blasting removes scale. Then, cold drawing through a die and restraightening improves surface properties and strength. Hot-rolled steel may also be cold finished by metal-removal processes such as turning or grinding. Wrought steel can be subsequently heat treated to improve machinability or to adjust mechanical properties.

Carbon steels may be specified by chemical composition, mechanical properties, method of deoxidation, or thermal treatment (and the resulting microstructure).

Composition

Wrought steels are most often specified by composition. No single element controls the characteristics of a steel; rather, the combined effects of several elements influence hardness, machinability, corrosion resistance, tensile strength, deoxidation of the solidifying metal, and microstructure of the solidified metal.

Effects of carbon, the principal hardening and strengthening element in steel, include increased hardness and strength and decreased weldability and ductility. For plain carbon steels, about 0.2 to 0.25% C provides the best machinability. Above and below this level, machinability is generally lower for hot-rolled steels.

Standard wrought-steel compositions (for both carbon and alloy steels) are designated by an AISI or SAE four-digit code, the last two digits of which indicate the nominal carbon content. The carbon-steel grades are:

10xx: Plain carbon

11xx: Resulfurized

12xz: Resulfurized and rephosphorized

15xx: Nonresulfurized, Mn over 1.0%

The letter "L" between the second and third digits indicates a leaded steel; "B" indicates a boron steel. Cast-carbon steels are usually specified by grade, such as A, B, or C. The A grade (also LCA, WCA, AN, AQ, etc.) contains 0.25% C and 0.70% Mn maximum. B-grade steels contain 0.30% C and 1.00% Mn, and the C-grade steels contain 0.25% C and 1.20% Mn. These carbon and manganese contents are designed to provide good strength, toughness, and weldability. Cast carbon steels are specified to ASTM A27, A216, A352, or A487.

Microalloying technology has created a new category of steels, positioned both in cost and in performance between carbon steels and the alloy grades. These in-between steels consist of conventional carbon steels to which minute quantities of alloying elements -- usually less than 0.5% -- are added in the steelmaking process to improve mechanical properties. Strength and hardness are increased significantly.

Any base-grade steel can be microalloyed, but the technique was first used in sheet steel a number of years ago. More recently, microalloying has been applied to bar products to eliminate the need for heat-treating operations after parts are forged. Automotive and truck applications include connecting rods, blower shafts, stabilizer bars, U-bolts, and universal joints. Other uses are sucker rods for oil wells and anchor bolts for the construction industry.

Mechanical properties

Cast and wrought products are often specified to meet distinct mechanical requirements in structural applications where forming and machining are not extensive. When steels are specified by mechanical properties only, the producer is free to adjust the analysis of the steel (within limits) to obtain the required properties. Properties may vary with cross section and part size.

Mechanical tests are usually specified under one of two conditions: mechanical test requirements and no chemical limits on any element, or mechanical test requirements and chemical limits on one or more elements, provided that such requirements are technologically compatible.

Method of deoxidation

Molten steel contains dissolved oxygen -- an important element in the steelmaking reaction. How this oxygen is removed or allowed to escape as the metal solidifies determines some of the properties of the steel. So in many cases, "method of deoxidation" is specified in addition to AISI and SAE chemical compositions.

For "killed" steels, elements such as aluminum and silicon may be added to combine chemically with the oxygen, removing most of it from the liquid steel. Killed steels are often specified for hot forging, carburizing, and other processes or applications where maximum uniformity is required. In sheet steel, aging is controlled by killing -- usually with aluminum. Steels intended for use in the as-cast condition are always killed. For this reason, steels for casting are always fully deoxidized.

On the other hand, for "rimmed" steels, oxygen (in the form of carbon monoxide) evolves briskly throughout the solidification process. The outer skin of rimmed steels is practically free from carbon and is very ductile. For these reasons, rimmed steels are often specified for cold-forming applications. Rimmed steels are often available in grades with less than 0.25% C and 0.60% Mn.

Segregation -- a nonuniform variation in internal characteristics and composition that results when various alloying elements redistribute themselves during solidification -- may be pronounced in rimmed steels. For this reason, they are usually not specified for hot forging or for applications requiring uniformity.

"Capped" and "semikilled" steels fall between the rimmed and killed steels in behavior, properties, and degree of oxidation and segregation. Capped steels, for example, are suited for certain cold-forming applications because they have a soft, ductile, surface skin, which is thinner than rimmed-steel skin. For other cold-forming applications, such as cold extrusion, killed steels are more suitable.

Microstructure

The microstructure of carbon and alloy steels in the as-rolled or as-cast condition generally consists of ferrite and pearlite. This basic structure can be altered significantly by various heat treatments or by rolling techniques. A spheroidized annealed structure would consist of spheroids of iron and alloy carbides dispersed in a ferrite matrix for low hardness and maximum ductility, as might be required for cold-forming operations. Quenching and tempering provide the optimum combination of mechanical properties and toughness obtainable from steel. Grain size can also be an important aspect of the microstructure. Toughness of fine-grained steels is generally greater than that of coarse-grained steels.

Free-machining steels: Several free-machining carbon steels are available as castings and as hot-rolled or cold-drawn bar stock and plate. Machinability in steels is improved in several ways, including:

Addition of elements such as lead (the "leaded" steels such as 12L13 and 12L14), phosphorus and sulfur (the "rephosphorized, resulfurized" steels such as 1211, 1212, or 1213), sulfur (the "resulfurized only" steels such as 1117, 1118, or 1119), and tellerium, selenium, and bismuth (the "super" free-machining steels)

Cold finishing

Reducing the level of residual stress (usually by a stress-relieving heat treatment)

Adjusting microstructure to optimize machinability

Alloy Steel ::-

Steels that contain specified amounts of alloying elements -- other than carbon and the commonly accepted amounts of manganese, copper, silicon, sulfur, and phosphorus -- are known as alloy steels. Alloying elements are added to change mechanical or physical properties.

COMPOSITION

A steel is considered to be an alloy when the maximum of the range given for the content of alloying elements exceeds one or more of these limits: 1.65% Mn, 0.60% Si, or 0.60% Cu; or when a definite range or minimum amount of any of the following elements is specified or required within the limits recognized for constructional alloy steels: aluminum, chromium (to 3.99%), cobalt, columbium, molybdenum, nickel, titanium, tungsten, vanadium, zirconium or other element added to obtain an alloying effect.

Technically, then, tool and stainless steels are alloy steels. In this chapter, however, the term alloy steel is reserved for those steels that contain a modest amount of alloying elements and that usually depend on thermal treatment to develop specific properties. With proper heat treatment, for example, tensile strength of certain alloy steels can be raised from about 55,000 psi to nearly 300,000 psi.

Subdivisions for most steels in this family include "through-hardenable" and "carburizing" grades (plus several specialty grades such as nitriding steels). Through-hardening grades -- which are heat treated by quenching and tempering -- are used when maximum hardness and strength must extend deep within a part. Carburizing grades are used where a tough core and relatively shallow, hard surface are needed. After a surface-hardening treatment such as carburizing (or nitriding for nitriding alloys), these steels are suitable for parts that must withstand wear as well as high stresses. Cast steels are generally through hardened, not surface treated.

Carbon content and alloying elements influence the overall characteristics of both types of alloy steels. Maximum attainable surface hardness depends primarily on carbon content. Maximum hardness and strength in small sections increase as carbon content increases, up to about 0.7%. However, carbon contents greater than 0.3% can increase the possibility of cracking during quenching or welding. Lead additions (0.15 to 0.35%) substantially improve machinability of alloy steels by high-speed tool steels. For machining with carbide tools, calcium-treated steels are reported to double or triple tool life in addition to improving surface finish.

Alloy steels are often specified when high strength is needed in moderate-to-large sections. Whether tensile or yield

Ferrous and Non Ferrous Metals

Documents

common ferrous metals

common nonferrous metals

term ferrous

alloy of copper

precious metals silver

metal of cyprus

ductile metal

copperbased pigments