Real Silver ????
Silver is 0.15
Nickel is 0.30
So you have about 3 times the galvanic potential that exists between copper and Nickel
Still.... in order for galvanic corrosion to take place, you need an electrolyte. The coolant may be perfectly electrolyte-less on day 1 but metals will leach in over time and therefore you can't depend on distilled water being electrolyte fee over time. I don't think anyone will say with certainty that corrosion won't occur .... but I think you could say that:
a) With the inhibitors in the pastel, you are a helluva lot better off than you would be with distilled water.
b) The rate of corrosion that would occur would be so slow that it would not be of any significance during the normal service life of the computer.
As Martin says ..... "But I don’t think you will completely stop corrosion. The idea is to keep it at bay long enough and/or reduce it for the intended service life."
. From everything I have seen or read, the pastel from Mayhems does an excellent job keeping it at bay. read more here;