Electroplating profiled workpieces using shaped anode - together with sacrificial anode to increase life of shaped anode

摘要

Electroplating process is for obtaining deposits on profiled surfaces of a workpiece using a shaped anode. In addn. to the shaped anode, at least one independent, sacrificial anode, soluble in the electrolyte, is used for the continuous replacement of the metal ions deposited on the workpiece and/or to maintain the desired metal ion concn. in the electrolyte during the process. Potential differences are pref. used between the shaped anode and the sacrificial anode(s) so the latter is/are anodic to the shaped anode. One pref. appts. uses an acid iron bath with a shaped anode of highly alloyed steel, e.g. S18/8 or graphite, and sacrificial anode of non-alloyed steel e.g. St37; other baths are acid- Zn or -Sn using sacrificial anodes of Zn or Sn. Maintains the balance between metal- and hydrogen-ions in the bath and prevents rapid wear of the shaped anode.