What are the knowledge points about aluminum?

Aluminum is a silver-white lightweight metal that ranks third in the earth's crust after oxygen and silicon. With a relatively small density, it is only 34.61% and 30.33% of iron and copper, respectively, and is therefore also called light metal. Aluminum is the world's second most produced and used non-ferrous metal after steel, with a density of about 1/3 of steel, copper or brass. Due to its light weight, aluminum is often used to manufacture land, sea and air transportation vehicles such as cars, trains, subways, ships, airplanes, rockets and spacecraft to reduce weight and increase payload.

In addition, according to the national standard (GB/T 1196-2008), aluminum ingot should be called "re-melted aluminum ingot". However, it is commonly called "aluminum ingot". It is produced by electrolysis using alumina-cryolite. There are two main types of aluminum ingots for industrial applications: cast aluminum alloys and deformed aluminium and aluminium alloys are processed products of aluminium produced by pressure processing: plates, strips, foils, tubes, rods, shapes, wires and forgings.

According to the national standard "Re-melted aluminum ingots are divided into 8 grades by chemical composition, namely Al99.90. Al99.85. Al99.70. Al99.60. Al99.50. Al99.00. Al99.7E, and Al99.6E" (Note: The number after Al is the aluminum content). The so-called "A00" aluminum, in fact, is an aluminum with a purity of 99.7%, which is called "standard aluminum" in the London market.