Oxide layer

An oxide layer is a thin film that forms on the surface of a metal when it reacts with oxygen in the air. This natural process, called oxidation, creates a protective barrier that prevents further corrosion or damage to the metal underneath. For example, rust on iron or the aluminum oxide on aluminum both serve to shield the core material. These layers can be very thin but are essential for maintaining the metal's integrity and longevity, often occurring naturally or intentionally applied to improve durability and performance.