During aluminum contacts oxidation, a thin aluminum oxide film forms on the surface of the metal. Aluminum oxide serves as an electronic insulator and capacitor dielectric. It dissolves in strong acids and alkaline solutions. It is stable over a wide range of pH from 4.0 to 9.0. Depending on the environment, aluminum oxide can be attacked by chlorides or sulfides.
Aluminum corrosion occurs when atoms of metal bond with oxygen. Aluminum alloys oxidize at a much faster rate than steel alloys. In most commercial aluminum alloy groups, magnesium, iron, and copper are used to provide corrosion resistance.
Aluminum alloys can suffer from galvanic corrosion when they are joined with other metals. This type of corrosion is relatively rare. However, it can occur if the conductors are exposed to a saline environment.
Aluminum contacts oxidation can be controlled by using an alumina barrier to protect the aluminum. A scotbrite pad can be used to clean the metal. Various conductor termination pastes are available to prevent oxidation at the conductor/connector interface. These pastes are safe for use in insulation.
Aluminium contacts oxidation can also be prevented by using an antioxidant paste. This paste is available in greased form and will help to stop oxygen from harming the aluminum.
Gold is a noble metal with exceptional electrical properties. Gold will not corrode and it will not form compounds. It is a poor electrical conductor, though. In order to make electrical contacts corrosion resistant, a combination of gold and nickel plating is used.