The enhancement of individual friction and corrosion properties of CrSiN coatings by Mo doping in seawater

Abstract

A series of CrSiN coating with various Mo contents were fabricated on Ti6Al4V alloys using a closed unbalanced magnetron sputtering system and their tribological and electrochemical behaviors were investigated. The results of friction tests suggested that oxidation behaviors of Mo element in the prepared coatings promoted the wear mechanism transforming to tribochemical wear, and the more Mo doping enhanced the tribological performance and presented the lowest wear rates of 2.27 × 10 −7 mm 3 /N.m and 8.12 × 10 −8 mm 3 /N.m for tribopairs of Cr( Mo )SiN/Al 2 O 3 and Cr( Mo )SiN/Si 3 N 4 , respectively. Besides, the corrosion product of MoO 3 reduced the corrosion rate of CrMoSiN coatings, CrMoSiN coating showed the low corrosion rate of 0.58 × 10 −3 mm/yr indicated that the passive behaviors of Mo element improved the corrosion resistance, and provided a good protection to Ti6Al4V alloys in seawater. • Cr( Mo )SiN coatings were successfully fabricated using the unbalance magnetron sputtering system. • The oxidization behaviors of Mo element decreased the friction coefficient. • The wear mechanism would be transformed to tribochemical wear with an increase in the Mo content. • The more Mo element doping enhanced tribological performance of CrMoSiN coating in seawater. • The corrosion rate and current density were slowed down due to the passive behaviors of Mo element on coating's surface.