Chrome Plating - Advantages and Disadvantages

Advantages and Disadvantages

The functional advantages of trivalent chromium are higher cathode efficiency and better throwing power. The better throwing power means production rates are greater. Less energy is required because of the lower current densities required. The process is more robust than hexavalent chromium because it can withstand current interruptions.

From a health standpoint trivalent chromium is intrinsically less toxic than hexavalent chromium. Because of the lower toxicity it is not regulated as toughly, which reduces overhead costs. There are other secondary health advantages:

• Higher cathode efficiencies lead to less chromium emitted into the air
• Lower concentration levels result in less chromium waste
• The anodes do not discompose

One of the disadvantages when the process was first introduced was that decorative customers disapproved of the color differences, however additives are now used to adjust the color. In hard coating applications, the corrosion resistance of thicker coatings is not quite as good as hexavalent chromium. The cost of the chemicals is greater, however this is usually offset by greater production rates and lower overhead costs. In general, the process must be controlled more closely than in hexavalent chromium plating, especially with respect to metallic impurities. This means processes that are hard to control, such as barrel plating, are much more difficult using a trivalent chromium bath.