Exfoliation corrosion
Encyclopedia
In metallurgy
, exfoliation corrosion is a form of intergranular corrosion
that manifests itself by lifting up the surface grains of a metal by the force of expanding corrosion products
occurring at the grain boundaries
just below the surface. It is visible evidence of intergranular corrosion. It is most often seen on extruded
sections where grain thickness is less than in rolled forms.
Metallurgy
Metallurgy is a domain of materials science that studies the physical and chemical behavior of metallic elements, their intermetallic compounds, and their mixtures, which are called alloys. It is also the technology of metals: the way in which science is applied to their practical use...
, exfoliation corrosion is a form of intergranular corrosion
Intergranular corrosion
Intergranular corrosion , also known as intergranular attack , is a form of corrosion where the boundaries of crystallites of the material are more susceptible to corrosion than their insides...
that manifests itself by lifting up the surface grains of a metal by the force of expanding corrosion products
Corrosion
Corrosion is the disintegration of an engineered material into its constituent atoms due to chemical reactions with its surroundings. In the most common use of the word, this means electrochemical oxidation of metals in reaction with an oxidant such as oxygen...
occurring at the grain boundaries
Crystallite
Crystallites are small, often microscopic crystals that, held together through highly defective boundaries, constitute a polycrystalline solid. Metallurgists often refer to crystallites as grains.- Details :...
just below the surface. It is visible evidence of intergranular corrosion. It is most often seen on extruded
Extrusion
Extrusion is a process used to create objects of a fixed cross-sectional profile. A material is pushed or drawn through a die of the desired cross-section...
sections where grain thickness is less than in rolled forms.