Aluminium
1) History:
The ancient Greek and Romans used aluminum salts for dyeing cloths and as a substance to close up gaping wounds, a lot like stitches that doctors use today. Aluminum is still used today to stop bleeding. Aluminum were once more valuable than gold. Napoleon III held a banquet where the honored guests were given aluminum utensils while the rest had to do with gold ones.
In 1761 Guyton de Morveau called the base alum ‘alumine”. In 1808 Humphry Davy called it aluminum as we know it today.
Pierre Berthier were the first person too successfully mine aluminum.
Aluminum was selected as the material to be used to build the tip of Washington Monument. At that time 30 grams of aluminum cost twice the amount of a common workers daily wage. Aluminum was a semiprecious metal at that time.
The casting of aluminum into moulds started as early as 1893. In 1886 the American Charles Martin Hall together with Frenchman Paul Heroult invented an electrolytic process called the Hall-Heroult process to extract aluminum. This method was much cheaper than any other method and is still used worldwide today. In 1907 they started the Aluminum Company of America shortened to Alcoa.
Germany became the world leader in the production of aluminum when Adolf Hitler came to power. However in 1942 the United States constructed new hydro powered project like the Grand Coulee Dam which generated enough capacity to produce aluminum to build sixty thousand warplanes in four years, something the Germans couldn’t match
2) General information:
Aluminium is found in the bauxite ore and what makes it remarkable is its ability to resist corrosion. It is very light weight as well. It has the remarkable ability to be bent and shaped without breaking. Aluminium is a superconductor allowing it to conduct electricity at low temperatures.
As it stand today aluminium has been mined for just over 100 years.
3) Properties:
Aluminium is a soft, lightweight metal that has a dull silver color caused by oxidation when it is exposed to air. It’s nontoxic, nonmagnetic and nonsparking.
Aluminium is one fifth as dense as steel and copper making it easy to be machined and casted. It has an excellent corrosion resistance.
Aluminium is one of the few metals that keep its silvery reflection even in a powder form making it an important component of silver paints. Aluminum mirror finish has the highest reflectance of any metal except silver, gold and copper. It is the second most malleable (bend without breaking) metal only behind gold and the sixth most ductile (to shape without breaking).
Aluminium has its limitations such as breaking down under stress very easily. Its breakdown point is almost zero comparing it to steel. This means that it would fail under repeated small loads. Another problem that is experienced with aluminium is its heat sensitivity. Aluminium unlike other metals will not glow red when it melts.
4) Usages:
Aluminum is the most used metal in the world even topping steel. Mirrors are made using normal float glass putting a thin layer of aluminum at the back of the glass. Here are just a few usages of aluminium:
- Transportation: automobiles
- Packaging: cans
- Construction: windows and doors
- Cooking utensils
- Electrical wiring
- Paints
