Matte black hard coating

WE WANT A BLACK MATTE HARD COATING TO THE surface OF THE STAINLESS STEEL 420 WHICH HAVE HRc 52 ON THE BODY. WE HAVE TRIED TO USE THE "QPQ" PROCESS, BUT THE COLOUR OF THE BLACK NOT BLACK ENOUGH, THE COLOUR IS LIKELY AS BLACK GREY COLOUR AND THE SURFACE ALWAYS NOT FULLY COATED, SOME WHITE DOT ON THE SURFACE MEANS THE COATING CANNOT COATED FULLY TO THE SURFACE.
PLEASE ADVICE ANY COATING, SOME PEOPLE TOLD ME THAT CAN BE USE THE PCD COATING AND THE CERAMIC COATING, IS THAT WORKED?

Hi, Billy. Can you tell us what the parts are and what other needs you may have to deal with? Indeed there are PVD processes and ceramic coatings available, and there is also black chrome. However, what you may wish to consider is fixing whatever you are doing wrong with the QPQ process which is leaving you with white dots, and then seeing if you can black oxide the parts for a full black color.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

PVD coating is the way to go. Matte black is achieve if the stainless steel substrate is not mirror finish, otherwise, the finish will be glossy black.