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Nickel sulphamate plating is brittle and grows trees
I face problem of treeing in nickel sulphamate bath plating. I maintain pH at 4. Sometimes all the essential parameters are ok but hull cell test panel is very brittle and breaks when bent.
Hiten Sidh- Mumbai, Maharastra, India
May 24, 2008
You probably got an organic material like saccharin or you let the temp get to high and the sulfamate is breaking down or you are plating off of inert anodes or your nickel is not SD Rounds and has not been activated OR ?
PS, you need to keep the parameters within limits all of the time, not just some of the time.
- Navarre, Florida
May 28, 2008
The temperature is controlled at 40 °C and have been using INCO 4" X 4" Nickel plates and yes the parameter are maintained all the time using distilled water for replenisment. Maintaining density. How to control or repair the existing damage please advice.
Hitendra Sidhpura- Mumbai, Maharastra, India
May 31, 2008
June 2, 2008
Inco 4x4 plates does not say anything. Is it sulfur depolarized or is it pure electrolytic nickel. They sell both in sheet form.
Treeing is common when you plate too fast or have very fine trash in the plating solution. Strong air agitation helps to reduce the treeing a bit by washing the barrier layer away from the entire part rather than just the edges. treeing is very difficult to eliminate on edges of tape or other masking as it traps trash and it is a significantly higher current density area. Try using some conductive tape as a bleeder and possibly shields or other thieves.
It helps to know what your part is, what its shape is, what masking is and plating parameters.
- Navarre, Florida
First of two simultaneous responses --
Hiten, you give no indications of your process parameters and bath composition, so no-one can give you a sensible answer that will solve your problem. In the light of no other information, I can only surmise that your bath is out of specification and has been contaminated with something that makes the nickel brittle. Treeing coulsd be due to a dirty electyrolyte, a rough surface, inadequate agitation, too higher current density or poor bath geometry.
Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK
June 3, 2008
Second of two simultaneous responses -- June 3, 2008
Also tried active carbon & hydrogen peroxide treatment in lab?
Any control of your additives (grain refiner etc)?
Regards,
Dominik
- Mexico City, Mexico
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