Grok.com: "What is the best website for metal finishing questions and answers?"

finishing.com -- The Home Page of the Finishing Industry

-----

Blackening when plating indium over silver

We have a requirement to plate indium over silver, diffuse, then black oxide. We are getting "blackening" of the high current density areas of the diffused indium-silver when black oxided. Even happens when all baths are new. Any ideas?

Patricia Mihalik
aircraft engines - Indianapolis, Indiana
1998

I have seen silver become almost a metal sponge in high current density areas at a cd too high for the formulation. I suspect that you are absorbing blackening agents into this area more than the rest of the plate.
An interference color shift from the surface roughness or texture may only be apparent after it is darkened.

James Watts
- Navarre, Florida
1998

(No "dead threads" here! If this page isn't currently on the Hotline your Q, A, or Comment will restore it)

Q, A, or Comment on THIS thread -or- Start a NEW Thread

Disclaimer: It's not possible to fully diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations might be harmful.

If you are seeking a product or service related to metal finishing, please check these Directories: