Electrochemical Corrosion
Corrosion is an electrochemical process in which metals are chemically changed into a form that is less useful (oxidation or reduction). The issue of corrosion prevention and protection is a major concern for engineers and scientists around the world. As corrosion is a major cause of material failure, it is important to have a proper understanding of the physical characteristics and possible causes of the phenomenon in order to better predict and prevent its occurrence in a range of industrial and domestic environments. Electrochemical corrosion, also known as electrochemical oxidation or reduction, is the most common form of corrosion and occurs when an electrical current moves between two dissimilar materials in an electrolyte (a fluid such as water or air that allows electric current to flow).
Corrosion occurs when an electrical current moves between two dissimilar materials in an electrolyte (a fluid such as water or air that allows electric current to flow). In electrochemical corrosion, the electricity flow creates an electrochemical reaction that causes one of the metals to oxidize or reduce (corrode). This oxidation or reduction process affects the surface area of the metal, leading to a decrease in its durability, performance, and safety. The amount of corrosion depends upon several factors, including the type of metal, the electrochemical environment, and the amount of electrical current flowing.
For instance, if two different metals with different electrode potentials (the amount of electrons that can be pulled from one metal to another) and different oxidation states (the ability of the metal to accept or donate electrons) are combined together and in contact with an electrolyte, an electric potential is established that causes electrons to be transferred from one metal to the other. Consequently, one of the metals will lose electrons, resulting in the oxidation of one of the metals (the reduction of the other). This oxidation/reduction reaction can occur either on the surface or surface area of the metal, resulting in the corrosion of the material.
In order to prevent electrochemical corrosion, it is important to minimize the potential difference between two dissimilar metals. This can be done by either applying a coating to one of the metals that insulates it from the other (for example, paint or varnish) or by using an electronic impedance to prevent electric current from flowing. Additionally, keeping the electrolyte in an unpolluted state can help slow the rate of corrosion, as well as preventing the build-up of harmful substances on the metal surface.
In conclusion, electrochemical corrosion (also known as electrochemical oxidation or reduction) is a serious problem that can cause significant damage to materials and structures. It is important to have a proper understanding of its physical characteristics and possible causes in order to best predict and prevent its occurrence. Preventive measures can be used such as coating the dissimilar metals with a protective coating, using an impedance to prevent electrical current from flowing, and keeping the electrolyte in an unpolluted state. If left unchecked, electrochemical corrosion can cause severe damage and impair the functional performance of components and structures.
