Effect of N2 partial pressure on ZrN coating orientation and tribocorrosion behavior and mechanism

Abstract

The ZrN coatings were prepared using multi-arc ion plating (MAIP) under different N2 partial pressures ranging from 10 % to 80 %. A comprehensive analysis of the microstructure, electrochemical behavior, and tribocorrosion properties of these coatings showed a gradual deposition rate decrease with rising N2 partial pressure. Analysis using GIXRD revealed higher N2 pressure led to a shift in crystal orientation from (111) to (200), initially increasing corrosion resistance but later declining. At 70 % N2 pressure, the ZrN coating exhibited the lowest values of capacitance Cpo (8.89 μF cm−2) and double-layer capacitance Cdl (1.14 × 10−7 F cm−2), with the highest values for the two-time constants τ recorded as 0.274 s and 5.749 s. The tribocorrosion behavior correlated closely with the corrosion performance, with the ZrN-70 % coating demonstrating superior tribocorrosion resistance and a minimal wear rate of 4.25 × 10−5 mm3/Nm. While the ZrN-80 % coating exhibited the lowest wear rate of 2.67 × 10−5 mm3/Nm, but was more susceptible to friction and corrosion synergy, causing localized failure. The outcomes reveal crystal texture significantly affected on the electrochemical and tribocorrosion characteristics of the coatings, primarily attributed to the robust passivation tendency and stability of the passivation film associated with the (200) crystal orientation. The dominant wear mechanism identified involves the interplay of adhesive, abrasive, and corrosion-erosion wear processes. Based on these results, ZrN coatings prepared using MAIP are expected to emerge as candidate materials for critical friction components in marine equipment or other corrosion-erosion environments.