Changes

The immersion processes are usually applied in the plating of the metals gold,silver, and tin. If the material to be coated is less precious, i.e. exhibits anegative standard potential against the metal ions in the surrounding solution, itgoes into solution releasing electrons while the more precious metal ions arereduced by absorbing electrons and being deposited on the electrode. Thisprocess can continue until the complete surface of the substrate is coveredwith a thin layer of the more precious metal. This limits the maximum achievablelayer thickness to approx. 0.1 μm ''(Table 7.5)''.