Rabu, 01 Juni 2011

Properties of Aluminium or Aluminum (Al)


Important properties owned aluminum that is widely used as engineering material:
- Weight type lightweight (only 2.7 g / cm ³, while the iron ± 8.1 g / cm ³)
- Good corrosion resistance
- Electrically conductive and good heat
- Easy fabrication / in form
- Its strength is low but the integration
(alloying) strength can be improved

The nature of corrosion of the aluminum material obtained by the formation of a layer of aluminum oxide (Al2O3) on the aluminum surface. This layer is made of Al corrosion resistant but also difficult to weld, because of differences in melting point (melting point).
Aluminum generally melt at temperatures of ± 600 degrees C and fused aluminum oxide at temperatures of 2000oC.

The strength and hardness of aluminum is not so high with the integration and heat treatment can be improved strength and hardness. Aluminium of commercial purity always contain non ± 0.8% is usually in the form of iron, silicon, copper and magnesium.

Other properties mnguntungkan of aluminum is very easily fabricated, can be poured (cast) by pouring anything.
Can be deforming in a way: rolling, drawing, forging, etc. extrusi. Become a complicated shape though.

History

(Latin: alumen, alum) The ancient Greeks and Romans used alum as a liquid cover pores and sharpeners of the coloring process. In 1761 de Morveau submit names to the base alum alumine and Lavoisier, in 1787, guessing that this is a metal oxide that has not been found.

Wohler is generally referred to as the scientist who succeeded in isolating this metal in 1827, although not pure aluminum have been successfully prepared by Oersted two years earlier. In 1807, Davy gave a proposal to name this metal aluminum (although not yet found the time), although in the end agreed to replace it with aluminum. The last name is the same as the many other elements that end with "ium".

Aluminum is also the spelling used in America until 1925 when the American Chemical Society decided to replace it with aluminum. To further the latter spelling is used in their publications.

Source


Method to retrieve the metal aluminum is by electrolysis alumina dissolved in cryolite. This method was discovered by Hall in the U.S. in 1886 and at the same time by Heroult in France. Cryolite, a natural ore found in Greenland today no longer used commercially to produce aluminum. His replacement is made cariran which is a mixture of sodium, aluminum and calcium fluoride.

Aluminum is the metal most commonly found in the earth's crust (8.1%), but never found free in nature.
Besides the minerals mentioned above, it is also found in granite and other minerals.
The properties

Pure aluminum, silver-white metal having the desired characteristics of the metal. He is light, not magnetic and not easily spattered, is the second easiest in terms of metal forming, and sixth in terms of ductility.
Usefulness

Aluminum is widely used as kitchen appliances, construction materials and metal dimanan thousands of other applications that are easy to make, strong and lightweight is required.

Although only 60% electrical conductivity of copper, but he used as material for light transmission.
Pure aluminum is very soft and not strong. But it can be mixed with copper, magnesium, silicon, manganese, and other elements to form a profitable properties.

This alloy is important usefulness in the construction of modern aircraft and rockets. The metal is evaporated in vacuum forming if the layer which has a high reflectivity for visible light and heat radiation. This layer underneath to keep the metal from oxidation process so as not to reduce the value of the coated metal. This layer is used to protect the glass telescopes and other uses.
Compound

Compounds that have great usefulness is aluminum oxide, sulfate, and the potassium sulfate solution. Aluminum oxide, alumina appears naturally as ruby, sapphire, corundum and Emery and used in the manufacture of glass and furnace heating.



Aluminum alloy
In a state of pure aluminum is too soft, low strength to be used in various engineering purposes.
By integrating techniques (alloying), these properties can be repaired, but often reduced corrosion resistance as well as tenacity.

A little manganese, silicon and magnesium, is still not a lot to reduce the corrosion resistance, but zinc, iron, tin, and copper is drastically lower the corrosion resistant properties.
Aluminum alloys can be divided into 2 groups:
1. Wronglt Aluminum alloy (sheet)
2. Costing aluminum alloy (cast bar)

 
Aluminum (or aluminum, aluminum, aluminum, alminium) is a chemical element. Coat aluminum is Al, and atomic number 13. Aluminum is the most abundant metal.

Aluminum is not the kind of heavy metal, but an element which amounted to about 8% of the earth's surface and the third most abundant. Aluminum contained in the use of food additives, antacids, buffered aspirin, astringents, nasal sprays, antiperspirants, drinking water, automobile exhaust, tobacco smoke, use aluminum foil, cookware, cans, ceramics, and fireworks.

Aluminum is a good electrical conductor. Light and strong. It is also a good conductor for heat. Can be hammered into sheets, drawn into wire and extruded into bars with a variety of cross-section. Corrosion resistant.

Aluminum is used in many ways. Most of it is used in high-voltage cable. Also widely used in window frames and fuselage. Found in the house as a pan, soft drink bottles, milk bottle caps, etc.. Aluminum is also used to coat the car lights and compact disks.

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