Black Chrome Again
Can you give me a procedure for the black chromium plating process?
Q. I would like to know more about the black chromium plating process. Can you give me a procedure for the process? T.B.
A. Black chrome has been used for many years, primarily as a decorative finish. Most of the black chromium plating processes are proprietary in nature. The major problem with the process is getting consistent color and deposit characteristics. Sometimes a black chromium deposit is plated over a regular chromium deposit. There are proprietary processes based on both hexavalent and trivalent chromium.
A typical bath formulation is given in the table below:
| Component | Concentration |
|---|---|
| Chromic acid | 250g/L |
| Acetic acid | 260 g/L |
| Barium acetate | 7.6 g/L |
| Operating Conditions | Range |
| Temperature | 100°F |
| Current density | 40-90 ASF |
While the above formulation will give you a decent finish, you will be much better off if you use a proprietary formulation.
Related Content
-
Innovation in Plating on Plastic
Plating on advanced plastics solution offers improved adhesion, temperature resistance and cost savings.
-
Possibilities From Electroplating 3D Printed Plastic Parts
Adding layers of nickel or copper to 3D printed polymer can impart desired properties such as electrical conductivity, EMI shielding, abrasion resistance and improved strength — approaching and even exceeding 3D printed metal, according to RePliForm.
-
Advantages to Pumped Eductor Agitation
Not all agitation methods are created equally. Pumped agitation with eductor nozzles can improve process tanks and quickly show a reduction in operating costs while keeping staff safe, following environmental legislation and preventing pollution.
