Summary for nickel plating brittleness Discussion
Nickel plating brittleness is the key issue in this thread, where V. Venkappa reports nickel electroplating over copper on mild-steel switch brackets peeling when the legs are folded during assembly. Ted Mooney advises first locating where the separation occurs: if it is between the substrate and copper, the problem is likely pretreatment; if there are multiple nickel blisters, it may be laminar plating from reprocessing or interrupted nickel plating; and if the nickel itself is cracking, the deposit is probably too brittle. Khozem Vahaanwala Saify adds that bright nickel is often brittle and suggests switching to a sulfamate nickel coating for better ductility. The discussion also points readers to nickel-plating references such as the Nickel Plating Handbook and the INCO Guide to Nickel Plating.
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Q. Hello,
I am from Brazil and here electroforms are not used. I have a bath of nickel sulfamate and I am having problems. The deposited nickel is brittle. Can anybody help me? Excuse me my English it is bad.
ALVARO PINHEIRO
electronics – SÃO PAULO, BRAZIL
2004
A. Without knowing what you are doing, your problem cannot be solved. Brittleness in an electroform can be due to almost anything, ranging from bath contamination through to the wrong (or out of specification) solution, wrong current density, wrong pH, wrong anodes and wrong temperature. You must provide details of what you are doing before anyone can help you.
Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK
The Sulfamate Nickel How-To Guide
by David Crotty, PhD & Robert Probert
Q. I am forming cavities of mold thermoplastic -temp. 50 °C -pH 4,0 -current 6amp/dm2 the deposition is on top of silver ink.
ALVARO PINHEIRO [returning]
altera – Brazil
? Bath composition?
Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK
Q. My bath has 500g/l of nickel, 35 g/l boric acid, 2 ml/l of mechanical washer, 1 ml/l of leveling
ALVARO PINHEIRO [returning]
altera – Brazil
A. Hi ALVARO. Surely there’s a typo there with regard to nickel concentration, which is 5 to 7X what it should be.
“Mechanical washer” is obviously a mistranslation, maybe you mean “hardener solution”? … maybe you should have none. I would suggest that you plate a Hull Cell ⇦ huh?
panel and tell us what you learn from it.
Luck & Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
Need quick confidential answers? $25
Need project assistance? $100/hr.
Q. Dear sir
We are getting Nickel Electroplating over Copper on mounting brackets of Switches made out of Mild Steel. But we find that the plating is peeling when we are folding the legs of the brackets during assembly. Could you guide as to how to reduce the brittleness to prevent the peeling.
Regards,
V.Venkappa
Manufacturer of Professional Grade Switches and Analytical Instruments – Hyderabad, Andhra Pradesh, India
2006
A. Are you doing the plating in house or outsourcing it, V.?
Try to determine where the separation is taking place. If between the substrate and the copper, it is probably a pretreatment issue. If there are multiple layers of nickel blisters, that may be laminar plating from reprocessing of rejects or interrupted nickel plating. If the nickel plating itself is actually cracking it is indeed too brittle. Bright nickel often is, and you may need to go to a sulfamate nickel coating.
Ted Mooney, P.E.
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
Need quick confidential answers? $25
Need project assistance? $100/hr.
A. If you have checked that the pretreatment is OK then you need to look at low leveling nickel brighteners and also get is a stress sequestrant that will nullify any compressive or tensile stresses in your deposit; after getting this into your nickel bath, ensure plating thickness within 5 microns.
Khozem Vahaanwala
Saify Ind
Bengaluru, Karnataka, India
See also:
• Topic 1269 “Need Ductility in Nickel Electroplate”
• Topic 4503 “How to reduce brittleness in Nickel Plating”