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- Clad redirects here. For the acronym, see CLAD.
Cladding is the covering of one material with another. It has different meanings depending on the context.
[edit] Metal
In metallurgy, cladding is the bonding together of dissimilar metals. It is distinct from welding or gluing as a method to fasten the metals together. Cladding is often achieved by extruding two metals through a die or pressing sheets together under high pressure.
The United States Mint uses cladding to manufacture coins from different metals. This allows a cheaper metal to be used as a filler.
[edit] Optical fiber
Regarding optical fiber in telecommunication, cladding is one or more layers of material of lower refractive index, in intimate contact with a core material of higher refractive index. (Source: from Federal Standard 1037C and from MIL-STD-188)
[edit] Building construction
In building construction, cladding may refer to the application of one material over another to provide a weather-proof layer intended to control the infiltration of weather elements. Cladding does not necessarily have to provide a water-proof condition but is instead a control element. This control element may only serve to safely direct water or wind in order to control run-off and prevent infiltration into the building structure. Cladding applied to windows is often referred to as window capping and is a very specialized field.
[edit] Nuclear reactor fuel
In nuclear reactors, cladding is the outer layer of the fuel rods, standing between the coolant and the nuclear fuel. It is made of a corrosion-resistant material with low absorption cross-section for thermal neutrons, usually Zircaloy or steel in modern constructions, or magnesium oxide with small amount of aluminium and other metals for the now-obsolete Magnox reactors. Cladding prevents radioactive fission fragments from escaping the fuel into the coolant and thereby from contaminating it.