The corrosion behaviour of macroparticle defects in arc bond-sputtered CrN/NbN superlattice coatings

Effect of chamber pressure on defect generation and their influence on corrosion and tribological properties of HIPIMS deposited CrN/NbN coatings

“…Any kind of growth defects are undesirable as these can restrain the coating functionality [17][18][19][20][21][22]. It can affect the surface roughness and surface finish, thus the tribological performance of the coatings can also be affected [18,19].…”

“…It can affect the surface roughness and surface finish, thus the tribological performance of the coatings can also be affected [18,19]. Nevertheless coating defects like pores, holes and voids can expose the substrate material to the corrosive media and accelerate the corrosion process [21,22]. Therefore, for improved and advanced industrial applications such as cutting tool and biomedical, a detailed understanding about coating defects and their influence on coating performance is very crucial.…”

“…Both the corrosion and tribological performances of CrN/NbN coatings (deposited by Arc or conventional magnetron sputtering techniques) have already been investigated [21,22,31,32]. The benefits of using HIPIMS over conventional PVD to deposit CrN/NbN have been also demonstrated [16,33,34].…”

Substrate Finishing and Niobium Content Effects on the High-Temperature Corrosion Resistance in Steam Atmosphere of CrN/NbN Superlattice Coatings Deposited by PVD-HIPIMS

“…For example, during arc evaporation deposition or during arc etching in arc bond sputtering (ABS) process, spherical droplets (macro-defects) are produced which compromise the coating effectiveness generating a galvanic couple between the defect and the coating matrix or stresses accumulation at the droplet-coating interface [20]. Also porosity and under-dense structures, which have been reported to be present in coatings deposited by sputtering techniques, can compromise mechanical and corrosion properties to a large extent [20][21][22][23].…”

“…For example, during arc evaporation deposition or during arc etching in arc bond sputtering (ABS) process, spherical droplets (macro-defects) are produced which compromise the coating effectiveness generating a galvanic couple between the defect and the coating matrix or stresses accumulation at the droplet-coating interface [20]. Also porosity and under-dense structures, which have been reported to be present in coatings deposited by sputtering techniques, can compromise mechanical and corrosion properties to a large extent [20][21][22][23]. CrN/NbN coatings deposited by high power impulse magnetron sputtering (HIPIMS) technique have shown to overcome all these drawbacks, retaining the good adhesion produced by arc techniques, as well as the smooth dense structures produced by sputtering techniques [21][22][23].…”