Where the
world gathers for metal finishing
Q&As since 1989


-----

Molecular cause of popping chrome laminate

I know chrome laminate will pop if the current is increased abruptly, but I don't understand why increasing the current slowly solves the problem. I would like to know what causes it on a molecular scale.

Mark Robison
Engineer - Layton, UT, USA
September 15, 2009

---

Placate those of us that do chrome plate and not call it a laminate-it is chrome plating.
An abrupt rise in the current will cause it to plate chrome to chrome faster than it can form the required molecular bond to the parent metal.
This said, there are a very few cases where you will intentionally raise the current to a high level extremely fast and then fairly quickly lower it to a beginning voltage and raise it slowly. No idea why, but it seems to prep the metal.
Also rapidly raising the current on a large part that has NOT been pre warmed will have a layer of chrome with one level (size) and the part that will grow as it heats up. Not terribly important on thin builds (flash) and on tiny parts, but it is serious on large parts. They will delaminate.
Notice, I used that bad word.

James Watts
- Navarre, Florida
September 16, 2009