Wednesday, July 7, 2010

Effect of Metal Impurities to Electroplating

Metal that is converted into ion in the solution of electroplating bath can effect to the electroplating result. By effect of chemicals on the electroplating bath and by some electric current that flow through the solution can make the metal dissolved on the solution and change to metal ion. Metal that dissolved in the solution called as Cation.

Cation that may contain in the chromium plating baths include of chromium (III) (CrO32+), iron ( Fe2+), copper (Cu2+), nickel (Ni2+), zinc (Zn2+), and Sodium (Na+). Chromium (III) merge when baths are operated with too large cathode area or too small area, or when organic matter is introduced. Chromium (III) content can be kept down by increasing the area of the lead anodes used relative to the cathode area, or where this is practical, by electrolyzing the solution for a time with a relatively large anode area and small cathode area. Other metalic impurities may be introduced into the bath in various ways. If permitted to accumulate, they cause an increase in the resistivity of the bath.

Impurities on the electroplating bath can make the result change to dark color from that early should be bright. The result sometime difficult to bright or cause the result of electroplating can not be smooth. This impurities should be removed from the bath or at least to lessen by filtering after settling overnight and then decanting.