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Physically, chemically and mechanically, aluminum is a metal similar to steel, brass, copper, zinc, lead or titanium. It can be melted, cast, formed and machined in a similar way to these metals and conducts electric currents. In fact, often the same equipment and fabrication methods are used as for steel.
Aluminum is a very light metal with a specific weight of 2.7 g/cm3, about a third of that of steel. This cuts the costs of manufacturing with aluminum. Again, its use in vehicles reduces dead-weight and energy consumption while increasing load capacity. This also reduces noise and improves comfort levels.
Its strength can be adapted to the application required by modifying the composition of its alloys. Aluminum-magnesium-manganese alloys are an optimum mix of formability with strength, while aluminum-magnesium-silicon alloys are ideal for automobile body sheets, which show good age-hardening when subjected to the bake-on painting process.
Aluminum naturally generates a protective thin oxide coating which keeps the metal from making further contact with the environment. It is particularly useful for applications where it is exposed to corroding agents, as in kitchen cabinets and in vehicles. In general, aluminum alloys are less corrosion-resistant than pure aluminum, except for marine magnesium-aluminum alloys. Different types of surface treatment such as anodising, painting or lacquering can further improve this property.
Electrical and Thermal Conductivity
Aluminum is an excellent heat and electricity conductor and in relation to its weight is almost twice as good a conductor as copper. This has made aluminum the first choice for major power transmission lines. It is also a superb heat sink for many applications that require heat to be drained away rapidly, such as in computer motherboards and LED lights.
Aluminum is a good reflector of visible light as well as heat, and that together with its low weight, makes it an ideal material for reflectors in, for example, light fittings or rescue blankets. Cool roofs made of coated aluminum are invaluable in reducing internal solar heat within a house, by reflecting up to 95% of sunlight.
Aluminum is ductile and has a low melting point and density. It can be processed in several ways in a molten condition. Its ductility allows aluminum products to be formed close to the end of the product’s design. Whether sheets, foil, geometrical configurations, tubes, rods or wires, aluminum is up to them all.
Strength at Low Temperatures
In contrast to steel, which rapidly becomes brittle at low temperatures, aluminum shows increased tensile strength as temperatures drop.
Impermeable and Odorless
Aluminum foil is only 0.007 mm in thickness, but is still durable and completely impermeable, keeping any food wrapped in it free of external tastes or smells. It keeps out ultraviolet rays as well.
Moreover, the metal itself is non-toxic and odorless, which makes it ideal for packaging sensitive products such as food or pharmaceuticals. The fact that recycled aluminum can be used reduces the carbon footprint for this stage of food and beverage manufacturers as well.
Aluminum is non-magnetic, making it useful for electrical shieldings as in computer disks, dish antennas, busbars or magnet housings.
Aluminum is non-toxic and is used to make woks, pressure cookers and many other cooking utensils without fear. It is easily cleaned and does not contaminate the food at any stage.
Sound and Shock Absorption
Aluminum is an excellent sound absorber and is used for constructing ceilings. It is also used in auto bumpers due to its shock-absorbing properties.
Aluminum produces no sparks when it comes into contact with itself or non-ferrous metals.
Aluminum is 100% recyclable and recycled aluminum is identical to the virgin product. This makes it a much more cost-effective source material for production runs. The re-melting of aluminum requires little energy: only about 5% of the energy required to produce the primary metal initially is needed in the recycling process.
Sources and Further Reading
This article was updated on 25th June, 2019