Metal finishing Q&As since 1989
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Improve Brightness in Sulphamate Electroforming bath
February 25, 2009
Hello
I work with a sulfamate electroforming bath with out chloride's and with sulfur-nickel pellets.
We are made copies from a mandrel, but the brightness is still low. We want to improve that quality. I read about saccharin, and other organic compounds, but they affect the mechanical properties, and the ductility is also one of our priorities.
did you know how I can improve the brightness?
The operation conditions :
Nickel sulfamate 85-120 g/lt
boric acid 30-45 g/lt
Temperature 48-58 °C
Current 1.5 to 3.5 amp/dm2
PH 3.8-4.2
product designer - Mexico
I understand that excessive roughness can be a problem but brightness is not exactly a property that one expects from a sulfamate deposit. This chemistry was developed for functional deposits, not decorative ones. Brightness would be on the non important side of your electroform. Or am I missing something? Additionally, your nickel sulfamate concentration seems too low. Could it be a typo and you are talking about metal concentration?
Guillermo MarrufoMonterrey, NL, Mexico
February 28, 2009
IT'S NOT A GOOD IDEA TO ELECTROFORM BRIGHT NICKEL BECAUSE YOU ARE ADDING A LOT OF STRESS IN THE COATING.
IS BETTER IF YOU WANT YOUR PRODUCT BRIGHT TO ADD ANOTHER NICKEL BRIGHT BATH AND ADD 4-5 MICRONS AS A LAST LAYER,THIS WILL BE ENOUGH TO IMPROVE THE APPEARANCE.
Bnei Berak, Israel
March 3, 2009
Adjust at first to proper parameters your tank. Then also small additions of grain refiner will improve a little bit the appearance without affecting much the ductility.
Either way, if you really want to have a bright nickel deposit, then you should consider to contact your local provider which normally provides bright nickel systems with a good balanced ductility properties
- Mexico City, Mexico
March 5, 2009
PROPRIETARY CHEMICALS ARE AVAILABLE AS REQUIRED.
KINDLY CONTACT GOOD CHEMICAL SUPPLIER IN YOUR CITY.
WITH REGARDS,
Ajay Raina
Ludhiana, Punjab, India
March 11, 2009
Consider to put some leveling agent and conduct hull cell test to find the suitable current density to obtain desired brightness.
Steven foong- Malaysia
March 28, 2009
Add between 0.1 and 0.4g/l sodium saccharin. This will give you a bright deposit and also increase the hardness. it will also affect your tensile stress; the lower the saccharin the lower the tensile stress and it can even remain compressive
Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK
April 2, 2009
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