Hi Horace. You write: >One way to adjust the relative contents of various metals in a codeposited >matrix is to use multiple anodes and control the relative current in each >during the deposition process. Provided the deposition environment is well >cleaned, it would hopefully be possible to create alloy compositions with >adequate control.
I've been all over this one, and I can say that electrolytic codeposition is a monster of a process for manufacturing purposes and not even very good for making lab prototypes. I've had OK luck with combinations like zinc and nickel, or situations where one metal will readily dissolve in another ( for example, mercury plated on just about any substrate will form an alloy in a few hours time ). I think you'd have much better luck using a sputtering technique. It's hard enough to control the chemistry with a single anode, trying to maintain ionic concentrations with different metal anodes is a nightmare. For my experimental work, I'd mix up a batch of electrolyte and use carbon or platinum anodes, replacing the solution when the ion balance would inevitably change. Useless for production work but I could make a few codeposited cathodes for testing purposes pretty reliably that way. I recommend this method if you do any casual experimenting. If you know of some system for depositing carbon, I'd love to hear it. I've never tried it, and am curious enough to get some of that gear out of storage if you know of a way to do it. One thing which did sort of work, along the lines you mention, was to use heavy stirring in a nickel bath and pour active carbon powder into it. The powder would codeposit with the nickel, although not in the intimate manner of a true codeposition. A while back, someone here on Vo, ( Terry maybe? ) posted a link to a story about fullerene cages containing metal atoms. Sounds like a natural candidate for CF experimenting. K.
