Stainless steel in Ultrasonic Bath with Nitric Acid

TO Whom it May concern:

I am working with an ultrasonic bath and will be using a weak to 3 Molar nitric acid bath. I wish to fabricate the tip of the acoustic horn out of something other than aluminium, which will dissolve in nitric acid. One suggestion was that I just use a stainless steel, since the nitric interacts with the surface and replenishes the oxide layer. Another thought was to gold plate the stainless. Suggestions?

I believe you have answered your own question- The nitric acid reacts with the stainless to replenish the oxide layer, which is exactly what you want. If this somehow is not resistant enough, many plastics are rigid enough to pass the relatively the same amount of vibration as softer alloys, and won't corrode.

Good Luck!