Macro-etchant for Nickel alloys

[dacf]

I am trying to find an acid mix that will adequately reveal the microstructure of a 35/45 chrome/nickel alloy. The current etchant I use is HN03 HCL H20 mix, which is OK for 25/35 alloys.

Where can I find info on etching high nickel-based alloys?

 

[metengr]

For nickel-based alloys you could try either of these two etchants;

Kallings #2
CuCl(2) - 5 grams
HCl - 100 ml
Ethanol - 100 ml

or

Marble's Reagent
CuSO(4) - 10 grams
HCl - 50 ml
DI water - 50 ml

You could add (drops) of sulfuric acid to the etchant to increase activity