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"Coloring thin nickel foils"
Q. I am interested in a coating or coloring process to color thin (0.002-0.003") nickel foils. Does any possible process exist?Steve Schwall
consulting engineer - Chicago, Illinois, USA
A. Immersion in 25% nitric acid at room temp for a few seconds will turn them black.
Jeffrey Holmes, CEF
Spartanburg, South Carolina
A. You can use next solution:
240 gms sodium thiosulphate [affil. link to info/product on Amazon]
25 gms copper acetate [affil. link to info/product on Amazon]
30 gms citric acid
1 lit water
16 °C temp.,20- 300 sec immersion time
According to Fishlock: Metal Coluring,Teddington 1962.
- Zagreb, Croatia