This technology encompasses various techniques and materials, and has wide ranging applications. For corrosion control coatings on steel structures, metallizing refers to the thermal spraying of zinc or aluminum alloys as a coating directly onto steel surfaces. An airstream sprays the molten metal onto the steel surface in a thin film. Once the metal strikes the steel it resolidifies quickly to become a solid coating.
Metallized coatings provide corrosion protection to steel by sacrificial and barrier protection.
Due to the electrochemical reaction between steel and zinc or aluminum in an aqueous and salt-contaminated environment, these coatings tend to sacrifice themselves to protect the steel at the site of any damage or holidays in the coating. This sacrificial protection is akin to the protection provided by zinc-rich primers or galvanizing. The metal or metal alloy is supplied in wire or powder form and is fed through a heat source and liquefied. Once on the surface, the liquid metal cools and drys very quickly to form a continuous protective coating over the steel surface. Recent reports have measured metallizing application rates similar to conventional air spray paint application rates with this new equipment.