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Nickel (only!) Plating onto Aluminium

I am trying to find a method of depositing up to 5 microns of Ni onto an Aluminium (pure) substrate. I wish to do this without using electroless techniques (no P or B in the coating) nor 'zincating'. I have tried cleaning in HNO3 solutions and using both the woods strike bath and a sulphamate bath but to no avail - found that Cl and Al aren't the best of bed fellows!.

Are there any Ni baths out there which I can formulate and are are slightly alkali in composition?

Any comments/thoughts appreciated!

Many thanks

Mark Craig,
PhD Student, Cranfield University, UK

Mark Craig
Student - Cranfield, UK
2007

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First of two simultaneous responses --

Check with brush plating reputed vendors (the best advertise here). They have special activating solutions and processes w/o zinc as well as neutral or slightly alkaline nickel formulas. Remember tht a superior initial condition of the aluminum surface is of utmost importance (particularly regarding pitts).

Guillermo Marrufo
Monterrey, NL, Mexico
2007

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Second of two simultaneous responses -- 2007

Brush platers achieve a reasonable adhesion of nickel to aluminum. Tank platers need to use a minimum of a zincate.
Brush plating is not uniform in thickness.
I believe that in your country that it is referred to as tampon plating.

James Watts
- Navarre, Florida

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One thing I dabbled with some years ago was jet plating - using a high velocity lamellar jet of electrolyte onto a target. There are numerous technical difficulties with the technology, but it has been around for many years after being invented by NASA. It is also known as "high speed metal deposition". I was reasonably successful in putting nickel onto aluminium and I hadn't even bothered to pretreat the aluminium, not even cleaning it! It is quite feasible to achieve electrolytic deposition rates of 1 micron per second with reasonably conventional nickel solutions. The technique needs refining, but it may be suitable for your needs.

Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK
2007