Electroformed (nickel sulphamate) record stampers are breaking

A. Either the nickel is too brittle or too stressed. What are your plating conditions and parameters?

A. What's your chloride level?

High chlorides are a common source of stress in sulfamate nickels.

First of two simultaneous responses -- 2007

A. The chloride level looks reasonable to me - you don't want too much with sulphamate or it becomes brittle. The only good job chloride does is promote anodic dissolution, and if you use S-nickel, you don't need it at all (in theory!). What is your nickel hardness and full bath composition? What are the plating conditions (temperature, current density, pH etc)? Have you done a Hull Cell test for impurities? The problem could be due to hydrogen embrittlement, co-deposition of another metal or numerous other factors. The more detail we have, the easier we can help you.

A. It is a balancing act between hardness and brittleness. Hardness is desired to reduce wear on the stamper and if the hardness is too high the stamper becomes brittle.

you did not mention pH. Too high a pH can make the stamper brittle. Typically a pH near 4 is used as this keeps the stress near zero. You can also be incorporating a lot of sulfur from the stress reducer into the stamper. High current density dummying will reduce the amount of stress reducer in the bath.

Hi guys, thanks for your answers...

We finally found a solution for this problem of ductility...

First of all, when I answered back, telling the bath was changed, there was less than 2 days of homogenation of the products... 2 days after, ductility was better, but not satisfying yet.

And in another hand, the "moistening" (I'm not sure of the word) was not so good...

So we increased the Sodium laurylate (Duponol) Level, and this was the reason why matrix were breaking ! (lack of duponol)

It seems that this kind of chemical product is added in order to reduce hydrogen pits AND to increase ductility...thing we ignored...

So, thanks a lot for all your ideas and advices, but our problem is now resolved... :)

I wanted to mention here that Finishing.com is a very good website, trying to help everybody's problems, giving some advices by experimented professionals and not "students" pseudo-professionals as we can see in other websites. It must be noticed !

Thanks everybody, and keep up the good work!

Thanks for the feedback and the compliment, Jonathan. We do not discourage responses from students or pseudo-professionals, but we do hope that the questions receive enough exposure that someone can offer a really good answer. In this case you did receive responses from four true professionals and we thank them!

A. I do not believe that adding more wetting agent increases ductility or reduces brittleness. This is most likely not the root cause of the problem.

Johnathon, What else did you do during the 2 days before the stampers became less brittle.

Was the bath just maintained at operating temp with filtration?
Did you carbon treat the bath?
Did you keep plating stampers and the quality gradually improved?
Were any chemistry changes made?
Did you dummy the bath?

What do the nickel plating experts think solved the problem?

A. Hi guys,

To answer your questions :

Was the bath just maintained at operating temp with filtration?

-> Yes, temperature maintained at 50°C and always filtered

Did you carbon treat the bath?

-> Active carbon was placed on filters during these two days

Did you keep plating stampers and the quality gradually improved?

-> We just let the bath filtering, no stampers were developed during 2 days

Were any chemistry changes made?

-> No changes were done in the chemical electrolyte, unless adding boric acid till obtain the pH desired

Did you dummy the bath?

-> Sorry I don't understand what dummy stands for... But I think I didn't... ;)



All we've done was simply let the bath filtered itself and keep the temperature about 50°C...I'm sure increase Laurylate sodium level had a benefic result on ductility, and this "idea" was confirmed by aplating specialist located here in Belgium...

Hope these answers to be helpful

Thanks,

A. Johnathon
thanks for the clarification. Just a couple of items

1. Boric acid is not used to adjust pH. The pH should be lowered with sulfamic acid and raised with either nickel carbonate or KOH.

2. Dummy plating is plating onto a sheet of metal that is folded to look like a washboard. it is folded so that there are both high and low current density areas on the same panel. The valleys will look dark if there is metallic contamination and the peaks will have pits if there is organic contamination. If the peaks and valleys on the dummy are identical then the bath is in good condition.

A. Hi Cokro.

We can't recommend specific brands. For one thing it sometimes results in a race to the bottom, with salespeople even posting with fictitious names, posing as satisfied customers :-)

If you are sure that simple nickel sulphamate will meet your needs, you can pick a reliable local commodity chemical supplier, but most platers are more comfortable getting the product from the established plating process suppliers. You can look in our Chemicals directory for these international suppliers, or you can simply look in your city for "Plating Chemical Distributors". Good luck.

Regards,