I'm facing copper rods to be used as electrodes in electrical discharge machining. I want to prevent any oxide layer formation on the copper electrode surface between time of facing the electrodes and time of using them in EDM.
Phosphoric acid"(88%) etches out all Copper oxides formed but it wont affect the Copper under the oxide layer.Less than one minute dipping is sufficient.
I have a suggestion, however i am not familiar with the process of EDM i work in ASIC component welding and i submerge copper components in mineral oil to prevent corrosion and oxidization if i have to leave it for an extended period of time before i get it to the bench. but i am not sure if oil densities or types would affect the machined rods or the way they are used
I assume that you want to use Spark Erosion in hydrocarbons. Then you can put the machined copper immediately in a hydrocarbon; either in your EDM oil or n-dodecane.
The etching with phosphoric acid is also possible, but requires a good cleaning of the acid, because otherwise more disturbing than their slight copper oxidation.
Thanks for the answers Amrutha, Prof. Johnathan and Prof. Schulze.
Prof. Schulze, the EDM oil which I'm using is paraffin oil. Since that is a hydrocarbon oil, the idea you suggested is very feasible. But I might also try some experimentation with deionized water. In that case, I think I will have to try deoxidising using phospohoric acid as suggested by Miss. Amrutha.
I don't think the DI water will work. It will sorb CO2 from the air and became acidic. Stick to the oils.
I would agree with Mr. Lasky, because even in the WEDM practice has been to use EDM oil. Deionized water does have environmental benefits, but the disadvantages by the electrochemical effects and the additional required deionization are greater manufacturing technology.
The whole thing must of course play no part in a scientific investigation. You should only consider whether the etching of a surface oxide layer (how great the film is it?) Is really necessary. The etchant then must in any case be completely eliminated, otherwise there are problems with the EDM.
you may use glycerene coating to prevent oxidation and it is also easy to remove it prior to final use. but ensure the purity of the glycerene.
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