Metal finishing Q&As since 1989
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Electroless Nickel Plating Corrosion Resistance
Q. I have an application in which corrosion is occurring between and Alkaline battery and a battery contact - presumably from moisture coming in contact with the battery and battery contact. We currently have a type I electroless Nickel plating (over spring steel) spec'ed on the component... Is there a better electroless Nickel plating that could resist this type of situation? Or does anyone know if this electrolytic reaction is more basic or acidic? Or maybe a better coating/material for this application?
Thanks in advance!
electronics mfgr. - Denver, Colorado, USA
2004
A. Obviously it's hard to do anything but guess from this distance, but I would tend to believe that electroless nickel is the right coating but that it is not being applied correctly. I don't mean to say that the plating shop is necessarily doing something wrong; you may also have specified too thin a coating or you may have lost control of the surface finish before plating.
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2004
2004
A. Ted is completely correct in suggesting that more investigation is needed to try to determine the cause of your corrosion problem. However, Type I EN allows any type of EN. With corrosion problems, normally high phosphorus types are preferred and provide significantly more protection than mid or low phosphorus types. You might consider specifying Type V EN instead.
Ron Duncan [deceased]
- LaVergne, Tennessee
It is our sad duty to note Ron's passing on Dec. 15, 2006. A brief obituary opens Episode 13 of our Podcast.
A. As for the type of reaction, Alkaline batteries use NaOH, ordinary lye, in the electrolyte... hence their name Alkaline. The Sodium Hydroxide is a base.
Tom Gallant- Long Beach, California, USA
2004
High phosphorous electroless nickel plating corrosion problem
Q. Our company has been supplying high phosphorous nickel plated alloy steel screws to a customer for a few years. Spec is per MIL-C-26074C at 5.1 to 7.5 µm thick 10-12% phosphorous and heat treated per section 3.5.2. Lately the customer has complained of the screws rusting and I have noted the same after leaving the plated screws in water for a few hours. Our plater says his process has not changed and the customer says his application is the same. My thought is that the plating is too thin but the plater says he has done it the same all along. Any information would be appreciated.
Gary
QA - Morgan Hill, California USA
August 4, 2014
A. Hi Gary,
Two things stick out, firstly the coating is far too thin to offer significant corrosion resistance, secondly if the heat treatment is a hardening treatment rather than a de-embrittlement then you affect the structure of the electroless nickel coating and again reduce corrosion resistance.
Now, all things being equal if these parts didn't suffer from corrosion issues before and now they suddenly do something has obviously changed somewhere, whether it the platers using a slightly different process (anything from the cleaning to the final heat treatment) or the conditions of use have subtly changed. We don't know, but something that used to work doesn't suddenly stop working!
Aerospace - Yeovil, Somerset, UK
September 2, 2014
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