Can we get jet black colour with CrCN coating

I am Angadala doing my research on decorative coatings. I heard that we will get jet black colour with CrCN coating. I tried this coating by putting 1:2 ratios of nitrogen and matahne at -50 v bias . but I failed to get the black colour. I changed the ratios frequently but I am getting CrN colour. can any one give rough idea to me in order to get black colour.

Hoping I will receive positive reply from highly respected ones.

Thanks & regards,

We tried the same thing and never got the jet black color, though we did darken the surface a bit. My guess is you need a very high carbon content in the coating to get the black color. Anyway, we wound up going to MoS2 for the black color. Not really a good solution -- MoS2 is a great solid lubricant coating, but is not very hard.

Dear Jim sir,

I got an excellent jet black colour with AlTiN coating on ss samples. Now I am trying to get the consistency to batch to batch .

Let me know your views .