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Etching Ni-Cr

A. Could you tell me the name of an acid that etches nickel-chromium alloy(%70 Ni-%30Cr). When you reached the desired depth of etching, you simply rinsed it with water which stopped the process. Thank You for your consideration in this matter.

Ercan Çalda
Student - Ankara, TURKEY
2005

Few people have spent time etching nichrome, the acids might be special to attack chrome, and it's not clear from your question whether you are doing art-work etching (to make a darker color), or dimensional etching (clean removal from metal which remains bright). Asking your past might be the best way to find out what that stuff was. Sometimes electricity is easier to get than exotic high-potential oxidizers. So, you might try applying 2 to 12 volts in 20% sulfuric and/or phosphoric acid. (nichrome positive, big stainless electrode negative.) Different effects from different voltages. Including a few percent sodium or potassium fluoride [affil links] might help too.

James Swenson
- Los Angeles, California, USA
2005