Everyone has seen a form of metal. They may see it on their automobile, on their bicycle, on parts of their home, or in other areas where metal is left exposed to the elements. Metals corrode when they are placed in environments that are chemically unstable for the metal. This is because most metals, with the exception of gold, platinum, silver, and copper, are not naturally found in their metallic state. Metals like iron are the result of processing minerals that are by nature not stable in their natural environment.
Metals attempt to revert to their stable mineral forms in different ways. Some metals will develop a film. This film will either completely stop the corrosion process, or it will slow it down drastically. The passive film that it develops is only about as thick as 12 atoms. But it is thick enough to provide protection against complete corrosion.
The basic definition of corrosion is when materials degrade as a result of how they interact with the environment. They degrade in the sense that their physical properties begin to deteriorate. Evidence of this degradation can be seen in a piece of metal becoming weaker as it corrodes because it loses its cross-section area. In other instances, the metal will eventually shatter because hydrogen cause it to become brittle. Also, metals corrode by cracking because of light exposure or electrochemistry.
As metals are exposed to elements and go through chemical reactions, they lose their electrons. This is completely opposite of what happens to nonmetals, which gain electrons through the corrosion process. When the atoms in metal lose their electrons, it is said that they have become oxidized.
Corrosion and oxidation are a huge problem, especially since so many buildings, appliances, and automobiles are built using metal. When a building is constructed with metal, the builders need to know that over time the metal will not corrode, weaken, and compromise the building’s structural integrity. For this reason, a chemfilm process is used. This process is designed to coat metal and protect it from eventual corrosion and oxidation.
Mankind’s ability to manipulate and use metal has changed the way that people interact with the world. It has led to the creation of some of the greatest wonders in mankind’s history. Thanks to the processes that are currently being used to protect and coat metal, the large buildings and structures that mankind has created today will be around for centuries to come.