Three CrN-based coatings were deposited on 17-4PH stainless steel substrate using plasma enhanced magnetron sputtering (PEMS) technique. The microstructure and corrosion resistance were evaluated to examine the effect of Si and C in the coatings. The three coating compositions were CrN(Cr 0.69 N 0.31 ), CrSiCN-1 (Cr 0.55 Si 0.014 C 0.14 N 0.3 ), and CrSiCN-2 (Cr 0.43 Si 0.037 C 0.24 N 0.3 ). The testing results indicated that with the increase of Si concentration, the coating microstructure transformed from B1 structure to B1 + Si 3 N 4 structure. All the three coating systems were subjected to electrochemical tests in 3.5% NaCl solution at room temperature. Potentiodynamic polarization results revealed that the CrSiCN-2 coating had a higher anodic current density and a lower corrosion potential when compared to the CrN and CrSiCN-1 coatings. Extended exposure in 3.5% NaCl caused several localized corrosion to the CrSiCN-2 coating due to the porous coating structure. Electrochemical impedance spectroscopic measurements demonstrated that the CrSiCN-1 has better corrosion resistance than CrN and CrSiCN-2.

No abstract

No abstract

No abstract

No abstract