The Property and Function of Aluminum
electric resistance

Aluminum, is a kind of chemical elements, whose chemical symbol is Al. the amount of the Aluminum in the earth’s shell is just only inferior to Oxygen and Silicon. It ranks the third. From this point, it can be concluded that Aluminum is one of the richest metallic elements in the earth’s shell. Among so many kinds of metals, except the steel, Aluminum belongs to the largest category. At the end of the 19th century, Aluminum finally made a great figure and became the competitive metal in the engineering application.

Why does Aluminum become so popular in so many industries, such as aviation, construction and automobile? There is no doubt that it has a direct relationship with the particular properties of Aluminum. To a great degree, the function of the material depends on its properties. Because Aluminum is characterized by so many excellent natures, its application is quite wide.

What properties does Aluminum have? In the following passage some of the main features will be introduced in detail. What comes first is that its density is every small. It is just about 2.7 g/cm. Although the metal Aluminum is relatively soft, it can be made into all kinds of Aluminum alloys. These alloys can be widely used in the plane, automobile, train and boat. What’s more, a great number of Aluminum and Aluminum alloys are also commonly applied in the cosmetic rocket, space shuttle and satellite. For example, a plane is composed of about 70 percent Aluminum and alloy. The second property is about its electric conductivity. The electric conductivity is only inferior to that of silver and copper. Although the Aluminum’s conductivity is about 2/3 of the copper, its density is only 1/3 of the copper.

Therefore, if the transported electricity are the same, the length of the Aluminum wire is about half of the copper wire. In the industrial application, the cost can be reduced if people use the Aluminum wire. Thirdly, Aluminum is a good conductor. Its thermal conductance is about four times of the iron’s thermal conductance. Owing to this property, Aluminum is often used to manufacture all kind of heat changer, heat sink material and cookware. The ductility of Aluminum is also a good property. Under 100 degree Celsius ~150 degree Celsius, Aluminum can be made into the thin aluminum foil. The foil is commonly used to pack the cigarette or candy. What’s more, owing to its low temperature resistance, Aluminum is the ideal material for the cryogenic equipments, such as cold store, freezer or the automobile driven in the polar circle.