BS EN ISO 26945:2008,Metallic and other inorganic coatings – Electrodeposited coatings of tin-cobalt alloy.
Electrodeposited coating of tin-cobalt alloy is characterized by its bright surface which is similar to decorative chromium coating. Hardness and wear-resistance properties of tin-cobalt alloy coatings are not equivalent to those of chromium coatings but are similar to those of tin-nickel alloy coatings (see ISO 2179).Thus tin-cobaltcoatings may be regarded, as far as surface lustre is concerned, as one of the possible alternatives to chromium coating. Due to its higher current efficiency (more than 70 %) tin-cobalt alloy coatings can be applied by rack and barrel plating processes to a wide range of complicated shapes and sizes, e.g. nuts, bolts,rivets etc.
BS EN ISO 26945:2008 specifies electrodeposited coatings of tin-cobalt alloy of approximate composition 75 % (mass fraction) to 80 % (mass fraction) tin, remainder cobalt, as a substitute for decorative chromium coatings of 0, 1 um to 0, 3 um thickness.Hardness and wear resistance properties of the coatings obtained are not equivalent to those of chromium coatings, but similar to those of tin-nickel alloy coatings.
Tin-cobalt alloy coatings can be applied by rack or barrel plating processes.
BS EN ISO 26945:2008 does not specify requirements for the surface condition of the basis metal prior to electroplating.