Anodising is an electrochemical passivation process used to improve the thickness of the alloy oxide layer on the internal surface of metallic parts by electrochemical means. This type of chemical process is used mainly to reduce friction and heat transfer from one component to another, with an emphasis on increasing the strength and durability of the object being treated. A thin layer of alloyed oxide is applied on the part or substrate, usually followed by a heat treatment (between five and ten seconds) to passivity is increased. This two-step process results in a harder, more ductile part that will better withstand wear.
The major benefit of anodising is that it improves the life of the object being treated. As heat passes through the object, the anodised aluminium oxide layer acts as a heat conductor, reducing friction to a minimum, and therefore extending the life of the object, as well as reducing heat corrosion. The process of applying the anodising agent and heat treating the object is also known as electrolysis, which means ‘anodic electrolysis’ or ‘electrochemical electrolysis’.
Anodising, like that from Poeton differs from electroplating in that the cathode, usually a small piece of metal, that is placed in an anodised slot in order to form the object is completely transparent. Instead of an electrical current passing through the cathode, current can only flow in one direction, which makes it ideal for applications where it is desirable to have the object clear of debris.