Sacrificial coatings are applied to surfaces both by bath and by selective brush plating to protect the underlying substrate from corrosion. The sacrificial coating corrodes in preference to the substrate, a property which is especially important when the substrate is scratched or damaged. Cadmium has long been used to provide this protection for structures, equipment, and fasteners. It is easy to plate and it has desirable properties that include corrosion protection, lubricity, antigalling, electrical conductivity, and low hydrogen embrittlement. Due to cadmium's toxic nature there is a trememdous amount of pressure to stop its use. Environmental concerns and regulatory mandates are driving manufacturers to find alternatives for cadmium. Therefore, identifying a suitable, non-embrittling cadmium replacement is of great interest. Tin-zinc and other zinc alloys are finding use in several industries for this purpose.
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