Another Cadmium Problem
What is causing black spots to appear on the surface of a steel part that is cadmium-plated and then treated with a chemical conversion coating?
Q. We have an ongoing issue with a steel part that is cadmium-plated and then treated with a chemical conversion coating. After a period of time, black spots start to appear on the surface. What is causing this? –M.C.
A. As mentioned above, there are two probable causes for this problem: inadequate rinsing and a porous cadmium deposit. Your final rinse procedure following the plating step should be alternating cold and warm rinses, ending with a warm rinse.
Check your cyanide concentration and make changes to bring the concentration up to specifications.
Why is it important for you to know this?
Getting the properties you paid for...
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).