Although long considered to have excellent resistance to corrosion, aluminium, like all other metals, may suffer from corrosion. Understanding aluminium corrosion phenomena requires expertise for various reasons:
The first difficulty arises from the fact that there are several families of aluminium alloy which do not all have the same resistance to corrosion.
The choice of alloy is therefore an important criterion from the point of view of resistance to corrosion. It is well known that aluminium alloys with the best mechanical properties are the most sensitive to corrosion. Cases of corrosion in service are frequently encountered when these are not used correctly.
The second difficulty may be caused by design in the drawing office or manufacture of the aluminium equipment in the factory.
The majority of cases of corrosion of aluminium are due to unsatisfactory construction methods, such as moisture retaining areas, poor welding, mismanaged contact with other metals, etc.
The third frequent cause of corrosion of aluminium is conditions of service that are poorly controlled by users or unfamiliar to the designers.
There are many other causes of corrosion, for example, incorrect storage conditions, transportation of part-finished aluminium alloy products, etc.