No registration or passwords; no pop-up ads -- just aloha, fun, & answers.
(as an eBay Partner & Amazon Affiliate earns from qualifying purchases).
Home /
T.O.C.
Fun
FAQs
Good
Books
Ref.
Libr.
Advertise
 
Help
Wanted
Current
Q&A's
Site 🔍
Search
pub  Where the
world gathers for metal finishing
Q&As since 1989



-----

Question about high stress of Mn-Co coating




Now I am doing the electrodeposition of Mn/Co alloys. For 1*1cm2 sample, I can get dense and uniform coating. However, for 1*1 inch2 sample, it is hard to get dense coating, or the stress in the coating is quite high, so when I try to get thicker coatings, the spallation will occur.
Then I add 4.5g/L into the bath, it still does not improve a lot. I wonder
(1) any other stress reducing agent will be useful?
(2) how to improve the current distribution for relatively big samples?
Thanks a lot.

Junwei Wu
student - Morgantown, West Virginia
2007



2007

I will guess that you are trying to use a chloride bath. This has such a high internal stress that any plating thicker than a flash will spall.
Can you go to a sulphate or a fluoboric solution? I did not find any reference to a sulfamate process, but you might be able to come up with a suitable one by making a cobalt bath and then adding Mn as a sulphate or similar compound if it is not soluble in sulfamic acid. This will probably have less stress than any other solution.
Look in "Modern Electroplating" [adv: this book on AbeBooks, eBay, Amazon] by Lowenheim for 3 sets of references which contain many publication citations for help. Your Library will have or can get this book if your advisor does not have it.

James Watts
- Navarre, Florida




(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:

 
Jobshops
Capital
Equipment
Chemicals &
Consumables
Consult'g, Train'g
& Software


About/Contact  -  Privacy Policy  -  ©1995-2024 finishing.com, Pine Beach, New Jersey, USA  -  about "affil links"