General Processing Steps

General Processing Steps

Explanation Of The Strike Electroplating Process

A strike is an optional preliminary electroplating step that puts a thin but highly adherent layer on. Typically, a strike is run:

  • at lower metal concentrations,
  • higher current densities,
  • and with few or no special additives.

A strike often produces significant gassing of the parts being plated. Basically, whatever sticks under those conditions is very adherent.

When Strike Plating Is Necessary

For certain bath and base material combinations a strike is necessary. A good example would be plating copper onto iron alloys using a copper sulfate bath. The copper sulfate bath has many advantages, particularly for rapid buildups, but if you put a piece of iron into the bath, a galvanic reaction takes place immediately whereby a non-adherent layer of copper forms and the subsequent build up of copper will flake off. You can avoid this problem by using a copper strike that is cyanide based and which does not have the galvanic reaction to worry about. After the strike, all the copper sulfate bath sees is copper.