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Peeling after nickel and gold plating

March 17, 2010

I am a Supplier Quality Eng. My plater is facing unsolved peeling issue after gold plating. We have tried several evaluation including additional of microetching process 30~1 min that end up with "dull" gold finishing. Hope that you can advise why material couldn't be coated properly during Ni or gold plating. Would the hardening process caused plating failure.

Raw part:
Becu CB101 Half Hard or equivalent (Be cu C17200 1/2H).
Heat Treat to Spring hard prior to plating (370 to 430 HV)

Plating Spec:
1st, Ni- 1.27 microns(min)
2nd, Bright Gold Plate-0.5 microns(min)

Suhana Supian
supplier quality - Penang, Malaysia

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First of two simultaneous responses -- March 20, 2010

CuBe is a problematic material to be plated specially if you heat treat.After the heat treatment you have tenacious oxides that hard to eliminate and cause later the problems in the plating shop.
You can avoid the oxides making the heat treatment in vacuum
or develop a special process to take out the oxides

Ricardo Burstein
Bnei Berak, Israel

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Second of two simultaneous responses -- March 22, 2010

Suhana,
During heat treatment, BeCu forms a tenacious beryllium oxide layer that has to be removed before any plating can be performed. ASTM B281 (Standard practice for preparation of copper and copper base alloy for electroplating and conversion coating) recommends a dip into a solution of 500 g/l Sodium Hydroxide at 130 deg.C for complete removal of the beryllium oxide film before electroplating. Alternatively, check out some of the earlier postings at finishing.com.

SK Cheah
- Penang, Malaysia

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Hi,
Gold plating can peel off from a nickel layer if you have too much och brightener in the nickel solution. The rinse between nickel and gold plating should be done in a clean rinsing water free from any nickel solution contamination.

You not mentioned anything about pretreatment steps they are using.

Regards

Anders Sundman
4th Generation Surface Engineering
Consultant - Arvika,
Sweden
March 22, 2010