Electrochemical Corrosion

Electrochemistry is a science that studies chemical reactions that involve electron transfer at the interface between an electric conductor (electrode) and an ionic conductor (electrolyte), which is a solution that conducts electricity due to ion motion. If an electrochemical reaction occurs on a metal surface, then this leads to metal deterioration or degradation and the electrochemical process is called corrosion. This means that a metal M becomes a metallic ion Mz \(+\) known as a cation having a positive electric charge. Corrosion is a natural process due to the instability of refined (manmade) metals or alloys, specifically in the presence of water and oxygen. In essence, corrosion is a natural degradation or deterioration of the lattice structure of a solid material due to electrochemical or chemical interactions with its environment. This implies that corrosion is a form of alteration or surface destruction of the crystalline or amorphous atomic structure of a refined metal M, which reverts to its natural ore state as a chemically stable oxide, such as hydroxide rust [FeO(OH).nH \({ }_2\) O]. Materials like aluminum and iron alloys can undergo a mechanism of self-protection by metal-oxide passive films with a few nanometers (nm) in thickness.