SAM4CH
Hazard to Others
Posts: 162
Registered: 16-7-2004
Location: TA
Member Is Offline
Mood: PERFECT
|
|
Electrochemical alloy formation
How can I formation alloy with any percent of metals like nickel/cobalt, copper/zinc by electrolysis!!
|
|
|
chromium
Hazard to Others
Posts: 284
Registered: 27-6-2005
Member Is Offline
Mood: reactive
|
|
As far as i know there is no general rule and working recipies are largely based on trial and error. Good electroplating manuals usally contain
information how to plate some alloys but you will not find data for any given precentage.
When all think alike, then no one is thinking. - Walter Lippmann
|
|
|
dedalus
Hazard to Self
Posts: 60
Registered: 13-4-2007
Location: New York
Member Is Offline
Mood: No Mood
|
|
There's a well established cyanide based chemistry for plating brass - the Cu/Zn ratio can be adjusted, but it's not an easy or straightforward
matter. The "free" cyanide content and the pH, more than the Cu/Zn ratio in the solution, affect the ratio that's deposited. There are also bronze
(Cu/Sn) plating baths. Those I know very little about.
I'm getting into Zn/Ni plating, lately. This is a very promising technology for replacing electroplated cadmium. I talk about it in more detail on my
page, at http://www.dedalusenviro.com/rohs.html
if you're interested. Zn and Cd coatings have the property of providing cathodic protection to iron, and Zn/Ni coating share this, until the Ni
content gets past abou 15%. Then, the steel beneath the coating becomes the anode...and the corrosion resistance of the object falls sharply.
|
|
|
ciscosdad
Hazard to Self
Posts: 76
Registered: 6-2-2007
Member Is Offline
Mood: Curious
|
|
Alloy electroplating
As far as I remember, the composition and concentration of the electrolyte is critical. The idea is to have the discharge potentials of the required
metal ions at specific levels. For example, to plate a 50:50 alloy, the potentials will have to be substantially the same. The required solutions may
possibly be figured out in advance, but from my limited recollection, you will have to experiment to establish what is needed for your specific
circumstances.. Tenmperature, pH, anode/cathode material, bath impurities and current density all have an effect.
Brass plating baths are cyanide based.
A patent search may unearth some clues. If I can find anything specific I'll get back to you. I seem to recall something in an old encyclopedia of
formulas I have.
Good luck.
|
|
|
chemist1066
Harmless
Posts: 3
Registered: 21-8-2007
Member Is Offline
Mood: No Mood
|
|
They do plate alloys: SnPb (solder), NiZn, also they plate alloys with very minor components ZnCo, ZnFe. Brass has also been plated. Gold plating has
a small amount of Co in it for hardness also. There are rules, basically, the deposition potential ofthe complex has to be somewhat close for both
elements.
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
