Physical Properties of Aluminum

Aluminum is never found as a native metal. Its main ore is bauxite. This mineral has been located in Alabama, Georgia and Arkansas in the United States. In the rest of the world Aluminum can be found mainly in the tropics as well as in areas that used to be tropical in the past. It is normally founding a weathered surface deposit. There are diverse minerals that can be found in the bauxite group and they can differ in color ranging from white to a dark red brown color. It is common to find in matrix that looks like a hard brown clay. The luster of Aluminum is dull; it has a hardness of 1 to 3; and a specific gravity of 2 to 2.5. Aluminum is a plentiful, light, and strong metal that can be used in many different ways. The main negative aspect to its use is the great amount of energy that is needed in order to refine it from its common ore, bauxite. The recycling of Aluminum scrap metal saves over ninety percent of the energy necessary to divide Aluminum from bauxite. Aluminum is only about one third as dense as iron, but some of its alloys, such as duraluminum are as strong as mild steel. Duraluminum is formed from 94.3 percent Aluminum, 4 percent copper, 0.5 percent manganese, 0.5 percent magnesium, and 0.7 percent silicon. Even though it is a great deal stronger than pure Aluminum, this alloy is not as resistant to corrosion and is frequently clad with pure Aluminum. Due to its lightness and strength, Aluminum is used a lot in the construction of aircraft. It has high electrical conductivity, 80 percent of which consists of copper, and is used instead of copper in huge electrical conductors. Its disadvantage there is its propensity to become oxidized at contacts, and has need of the use of contacts coated with an antioxidant. Aluminum is a very active metal, and something that cannot frequently be seen is that it quickly creates a barrier oxide layer on uncovered surfaces, holding back its contact. When Aluminum is very strongly heated it burns very rapidly in air, and when it is in the form of a fine dust it can also be explosive.