Electromotive series of alloys?

[DNIndustry]

I disolved the gold off of some cpu lids the other day . A mixed lot of ceramic P.Pros and Gold plate.
I used a 2.5 normal Hcl and minimal Naclo. the 80/20 solder on the p.pros went fine and the still plated lid took a bit longer. once It was done I went away for a few hours. came back and the lid had become coated in black fuzz. it got pretty thick.

When working with alloys what metal takes the precedence in the series or does it have its own potential based on the mix...Anyone get a new orp meter lately?

 

[butcher]

I don't know if this will help, certain metals will electroplate to other metals easier, potiential difference of these, I believe to be a factor, also the solution they are in can play a big part in this, type of acid, oxidizer, PH, impuritys, which other metals are in solution. if trying to study this I would look into electrolisis, and galvanic cells, EMF series, potiential difference, this my best guess.