What is corrosion? Explain its advantage and disadvantage.

Corrosion is the decay of metal when it is exposed to the elements in the environment. Scientifically, it is the oxidation of a metal which forms a layer of metal oxide on the top layer. Advantages of corrosion It protects the top layer of the metal. Since the oxide layer is formed on the metal, it prevents it from further oxidation, by protecting the inner layers. It prevents the air and water from seeping into the inner layers of the metal. sacrificial anodes like the zinc metal are used for such processes. It reacts with the oxygen in the air, to form zinc oxide. This zinc oxide acts as a protective layer and prevents the metal from further corrosion. The process of galvanic corrosion is practised, where two metals are in contact electrically, through an electrolyte. One metal erodes preferentially, compared to another. This prevents the actual metal from being corroded. Disadvantages of Corrosion Due to the reaction with oxygen and other elements in the environment, the purity of the metal is hampered. A major part of the top layer of the metal is lost, due to corrosion It changes the physical appearance of the metal. It changes the chemical composition and the appearance of a metal Reduces the life span of the metallic objects and is forced to replace it frequently The metal loses its efficiency. read less

Corrosion means degradation of material due to its reaction with its environment. Corrosion deteriorates physical properties of the metal DISADVANTAGES OF CORROSION — 1. Weakens material due to prolonged corrosive action. 2. loss, contamination, and deterioration of the appearance of a material. 3. safety, health and environmental risks due to corrosion, especially in manufacturing plants. 4. Corrosion tends to vent in technical malfunctions in machines. ADVANTAGES OF CORROSION — 1. Corrosion of a material has to be renewed, thus giving scope of continuous demand for materials. 2. Corrosion becomes advantageous when a surface produces an oxide film that will keep corrosion from proceeding further; which happens to aluminum metal. read less