Breviary Technical Ceramics






5.6 Corrosion

Corrosion refers to the reaction of a material with its environment, resulting in a measurable change in the material and capable of leading to corrosion damage (DIN 50 900). Originally, the term "corrosion" was only applied to metals, but nowadays it is generally used for any materials, including polymers, glass and ceramic.
Corrosion refers to the chemical attack of a medium on a material. In contrast, abrasion is defined as the mechanical interference of a solid body (the opposing body) with the main body of a tribological system. In most cases, corrosion increases the level of any abrasive wear.

In comparison to metals, ceramic materials may be considered resistant to corrosion, because their corrosion rates are a great deal lower than those of metals. There are significant differences in the types of corrosion and corrosion resistance between the different groups of ceramic material (silicate, oxide and non-oxide ceramic). Whereas corrosion in metals is an electrochemical process, the solubility of the material is the determining factor in the level of ceramic corrosion. The chemical composition and the microstructure are the key factors for low corrosion rates.


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