plating, anodizing, & finishing Q&As since 1989
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.
Becu CB101 Half Hard or equivalent (Be cu C17200 1/2H).
Heat Treat to Spring hard prior to plating (370 to 430 HV)
1st, Ni- 1.27 microns(min)
2nd, Bright Gold Plate-0.5 microns(min)
supplier quality - Penang, Malaysia
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
Bnei Berak, Israel
Second of two simultaneous responses -- March 22, 2010
During heat treatment, BeCu forms a tenacious beryllium oxide layer that has to be removed before any plating can be performed. ASTM B281 [affil. link] (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.
- Penang, Malaysia
March 22, 2010
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.
4th Generation Surface Engineering
Consultant - Arvika,