Alternating electrodeposition...

[Externet]

Hi all.

What to expect from electroplating a 'target' metal with two (or more)  different 'donor' electrodes cyclically switched on for few seconds ?   I do not have the equipment to experiment.

Example...  an iron 'target'  electrode getting electrodeposition from both submerged copper and tin electrodes in the same vessel but only one timely connected (powered) at a time...  With proper timing; would the iron be electroplated with bronze ?

Or... several  'donors'  creating a complex alloyed surface for corrosion/hardness/properties improvements  ?   Does such a practice exist in the industry ?

Edited October 15, 2017 by Externet

[John Cuthber]

In that case the cathode would be plated almost entreaty with copper because it's much easier to reduce to the metal than tin is.

Plating with alloys is possible, but difficult.

 

[Externet]

Thank you, John.  Good. Easy processes do not bring much merit.

Plating to the correct percentages an alloy ideally is composed of,  would then need different times or currents when a particular anode is switched on,  to establish a proper recipe, right ?

[Enthalpy]

Hi both,

It is done for nickel-cobalt alloys. These elements have very close properties, including the redox potential.

Instead of pulses, I'd use currents, which can be regulated exactly too.

I had hoped, but never tried, to run the multiple-sources deposition for long enough that the bath gets richer in the metal more difficult to deposit due to the difference in redox potential. At some point, and if the metals aren't too different so some equilibrium is reached, the proportion of dissolved source must impose the proportion of the deposition. I'd have put the desired target only then.

Though, I've heard only of Ni-Co, not even Ni-Cu,  so the process can't be easy.

What does exist is a deposited layer that incorporates other elements from the bath, and not only metals. Contractors can embed particles of Ptfe in Ni for instance.