(Chemical symbol Al) Silvery-white light-weight metal with high electrical and thermal conductivity. Al powder is combustible. Aluminium is the most widely used light-weight metal and is used for example as foil or in the form of profiles or cast parts. The surface of aluminium can also be activated by means of plasma. aktiviert werden. Forms a thin, transparent oxide coat when exposed to air. Plasma treatment in oxygen or air plasma can also be used to produce an oxide coat to protect the metal core. The aluminium oxide coat is stable in a neutral pH range and protects the metal from further oxidation.the substrates to remove contaminations. Alkaline solutions and many acids attack the oxide and the metal. Aluminium has a very high surface energy and is highly wettable, contrary to aluminium oxide. For this reason, it may be necessary to remove the aluminium oxide in a hydrogen plasma before coating. This particularly applies to electrical contacts because the oxide coat also impairs the electrical contact.