| Summary: | To increase wear resistance, (Zr,Nb)N, ZrN and (Zr,Hf)N coatings with columnar structures and (Zr,Ti)N and (Zr,Nb,Hf)N coatings with nanolayer structures were deposited on an AISI 321 stainless steel substrate. The samples with (Zr,Nb)N and ZrN coatings exhibited the best resistance to failure in the scratch test. The sample with the (Zr,Nb)N coating had the best wear resistance for the first 16,000 s. However, eventually the wear of this sample became notable, and after 20,000 s of testing, the lowest degree of wear was observed in the sample with the (Zr,Nb,Hf)N coating. The wear rate of the uncoated sample was 1.5 times greater than that of the sample with the (Zr,Nb,Hf)N coating. The (Zr,Nb,Hf)N coating also exhibited a low degree of indenter mass loss. The (Zr,Nb,Hf)N and ZrN coatings reduced the coefficient of friction (COF) most (COF of approximately 0.20–0.21, compared to COF = 0.28 for the uncoated sample). Defects (nanocavities) were detected in the interface area between the coatings and the substrate, which in some cases can have a negative effect on the wear resistance of the coating. The (Zr,Nb,Hf)N coating (72.07 at.% Zr, 24.87 at.% Nb and 3.05 at.% Hf) had the best wear resistance and a low friction coefficient.
|