Black Optical Coatings on 316L Stainless Steel

Letter 3309

Black Optical Coatings on 316L Stainless Steel

-

I have an application where we need to decrease the parasitic optical reflections on a 316L stainless steel part. The used light is around 890 nm wavelength.

What kind of black optical coatings are available?

Do you have any ideas on where I can look for this information?

Thank you for your help.

Pere Llosas
- Switzerland

-

I have seen black chromated alkaline zinc used over brass laser timing gears for an optical timing device which had similar optical requirements. In this case prior to black zinc, a woods nickel would be required in order to zinc plate the stainless. The black chromate had to be baby sat during the chromating operation due to the high QA requirements.

Ward Barcafer, CEF
aerospace - Wichita, Kansas

-

Try a room temp black oxide coating. Although this is not a true black oxide, it should provide a reasonably dulled almost matte finish.

Dan Brewer
chemical process supplier - Gurnee, Illinois

August 27, 2009

We use a process that produces a nice black iron oxide coat with a matte finish. We vacuum bake the parts to use in our UHV vessel. Usually there is some loose amount oxide that we wipe off/lightly sonicate. The specification for the process is:
mil-13924

For a matte finish that it is vacuum compatible you MUST also specify:
NO OIL, NO WAX, NO SEAL
NO TESTING

Alan Bobalan
- Irvine, CA, USA

Legal disclaimer boilerplate button