is the covering of one material with another. It has different meanings depending on the context.
, cladding is the bonding together of dissimilar metals
. It is distinct from welding
as a method to fasten the metals together. Cladding is often achieved by extruding
two metals through a die
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.
Regarding optical fiber
, 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
In building construction
, cladding may refer to the application of one material over another to provide a skin or layer intended to control the infiltration of weather elements, or for aesthetic purposes.
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.
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
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.