Investigation of monolayer–multilayer PVD nitride coating

Abstract

A thin monolayer and multilayer physical vapour deposition film was prepared on tool steel substrates using an unbalanced magnetron sputtering technique. Characteristics of multilayer (Mo/MoN, Ti/TiN, Cr/CrN, W/W₂N; A/B = 0·6∶0·3 μm) and monolayer (MoN, TiN, CrN, W₂N; 0·6 μm) coatings were investigated concerning the phase composition and coating adhesion. The multilayer film sliding against alumina (Al₂O₃) and steel balls (100Cr6) had good wear resistance and very long service life at room temperature compared to monolayer analogues. In order to evaluate the drilling performance in wet condition four surfactants, i.e. zinc dithiodiphosphate, sodium dodecyl sulphate, sodium hexametaphosphate and cetyl trimethylammonium bromide as 1 wt-% were used with polyalphaolefin base oil. A significant reduction in flank wear rate was measured under wet condition.

Keywords:

• PVD
• Monolayer
• Multilayer
• Friction
• Surfactant

Acknowledgements

The authors gratefully acknowledge the support from the faculty members of CTU-Prague and ISM-Dhanbad.