Nickel plating on Beryllium Copper

A. Hi Ranjit. A typical way to treat beryllium copper is to electroplate it for a measure of corrosion resistance plus good electrical conductivity, or optionally to add gold plating on top of that for best conductivity. Electroless nickel can offer greater corrosion resistance and wear resistance at the cost of some of the conductivity. Unfortunately, your inquiry is rather vague, not telling us what the component is, why it's beryllium copper, what properties you need to retain, or what the exposure situation is except than agriculture and ammonia is involved. So I can't even say whether a heavy coating of plastisol or some other totally different technology might be better for your needs. Give us some data please :-)

Luck & Regards,

A. The only thing special about beryllium copper is that it must be first plated in an acid solution. The only reason for "striking" is to leave copper in the sewer strike solution so that the main plating solution "sees" nickel instead of copper hence preserving the purity of your main plating solution. Just be sure you plate in an acid solution first.

A. A process I have used in the past is as follows:
1) Degrease the part(s)
2) Anodic alkaline clean
3) sulfuric acid dip
4) Sulfamate Ni plate
This process ensures a copper rich surface prior to Ni plate, and the removal of Be compounds that form on and just below the surface of the substrate. It is always a good idea to double check with your Ni supplier regarding cleaning and activation cycles. I have seen and plated BeCu successfully without a Wood's Ni strike. Good Luck!

A. Hi Martin,

If the component is not having complex geometry and plain surface then Wood's nickel strike can be attempted.

Because the covering power of Wood's nickel is poor, when the job is of complex geometry I prefer the sulfamate strike as otherwise the bath attacks the copper exposed and copper metal builds up in the bath. Sulphamate bath also keep it at 50 °C and max of 30 gm/lit of boric acid only to get fairly good coverage.

One factor to examine is the rinsing. Barrel plating can allow small drops of solution to be trapped in certain regions and unless very good rinsing and drag-out is performed there can be defects such as you described. Too many parts in a barrel can also be a factor. I would be sure to use a triple cascade DI H20 rinsing system and probably spray rinse as well whenever possible. Suppose two parts are nestled closely in the barrel and don't move about much. Suppose they have a couple of surfaces either in contact with each other or very, very close. In this circumstance, liquids may remain on the given surfaces and then when the barrel is brought to the next tank the excess solution is not immediately diluted into the tank but stays on the surface long enough to cause a defect/blister.

A. It is important to know if the blistering is between the base and the nickel - a cleaning problem, or between the nickel and the gold - a nickel passivation problem

Solvent cleaning is good
Soak cleaning should be sufficient - electrolytic cleaning does not work well in barrel plating
Rinse
sulfuric activate
Rinse
Nickel plate A standard watts nickel bath is all you need
Dragout
Rinse and immediately
Gold plate. Any delay will allow the nickel to passivate and cause poor adhesion
Dragout
Hot Deionised rinse
Warm air dry 200C is far too hot but will certainly show up any adhesion problems as you have seen.

Beryllium copper can have a Be rich phase at the surface that makes it extremely difficult to plate onto. You may need a light microetch like ammonium persulphate if this happens.

Actually, plating Be/Cu is easy. It is heat treating Be/Cu springs that causes sleepless nights!!