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Aluminium tubing is the worldwide most abundant metal and is the third most common element comprising 8% of the earth’s crust. The versatility of Aluminium tubing makes it the most widely used metal after steel.But there is also some details about physical principles should be known.
The article contains following；
1,Biological role of the aluminum tubing
2,Natural abundance of the aluminum tubing
3,Physical Properties of Aluminium tubing tubing
Aluminium tubing has no known biological role. In its soluble +3 form it is toxic to plants. Acidic soils make up almost half of arable land on Earth, and the acidity speeds up the release of Al3+ from its minerals. Crops can then absorb the Al3+ leading to lower yields.
Our bodies absorb only a small amount of the Aluminium tubing we take in with our food. Foods with above average amounts of Aluminium tubing are tea, processed cheese, lentils and sponge cakes (where it comes from the raising agent). Cooking in Aluminium tubing pans does not greatly increase the amount in our diet, except when cooking acidic foods such as rhubarb. Some indigestion tablets are pure Aluminium tubing hydroxide.
Aluminium tubing can accumulate in the body, and a link with Alzheimer’s disease (senile dementia) has been suggested but not proven.
Aluminium tubing is the most abundant metal in the Earth’s crust (8.1%) but is rarely found uncombined in nature. It is usually found in minerals such as bauxite and cryolite. These minerals are Aluminium tubing silicates.
Most commercially produced Aluminium tubing is extracted by the Hall–Héroult process. In this process Aluminium tubing oxide is dissolved in molten cryolite and then electrolytically reduced to pure Aluminium tubing. Making Aluminium tubing is very energy intensive. 5% of the electricity generated in the USA is used in Aluminium tubing production. However, once it has been made it does not readily corrode and can be easily recycled.
Density of Aluminium tubing
Aluminium tubing has a density around one third that of steel or copper making it one of the lightest commercially available metals. The resultant high strength to weight ratio makes it an important structural material allowing increased payloads or fuel savings for transport industries in particular.
Strength of Aluminium tubing
Pure Aluminium tubing doesn’t have a high tensile strength. However, the addition of alloying elements like manganese, silicon, copper and magnesium can increase the strength properties of Aluminium tubing and produce an alloy with properties tailored to particular applications.
Aluminium tubing is well suited to cold environments. It has the advantage over steel in that its’ tensile strength increases with decreasing temperature while retaining its toughness. Steel on the other hand becomes brittle at low temperatures.
Corrosion Resistance of Aluminium tubing
When exposed to air, a layer of Aluminium tubing oxide forms almost instantaneously on the surface of Aluminium tubing. This layer has excellent resistance to corrosion. It is fairly resistant to most acids but less resistant to alkalis.
Thermal Conductivity of Aluminium tubing
The thermal conductivity of Aluminium tubing is about three times greater than that of steel. This makes Aluminium tubing an important material for both cooling and heating applications such as heat-exchangers. Combined with it being non-toxic this property means Aluminium tubing is used extensively in cooking utensils and kitchenware.
Electrical Conductivity of Aluminium tubing
Along with copper, Aluminium tubing has an electrical conductivity high enough for use as an electrical conductor. Although the conductivity of the commonly used conducting alloy (1350) is only around 62% of annealed copper, it is only one third the weight and can therefore conduct twice as much electricity when compared with copper of the same weight.
Reflectivity of Aluminium tubing
From UV to infra-red, Aluminium tubing is an excellent reflector of radiant energy. Visible light reflectivity of around 80% means it is widely used in light fixtures. The same properties of reflectivity makes Aluminium tubing ideal as an insulating material to protect against the sun’s rays in summer, while insulating against heat loss in winter.