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:
|Acetic acid||260 g/L|
|Barium acetate||7.6 g/L|
|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.
White Bronze, Copper-Tin-Zinc Tri-metal: Expanding Applications and New Developments in a Changing Landscape
This paper deals with the renewed interest in applications for white bronze tri-metal (Cu-Sn-Zn alloy).
Masking is employed in most any metal finishing operation where only a specifically defined area of the surface of a part must be exposed to a process. Conversely, masking may be employed on a surface where treatment is either not required or must be avoided. This article covers the many aspects of masking for metal finishing, including applications, methods and the various types of masking employed.
An alternative product for passivation...