Multilayer interfaces to achieve excellent corrosion and tribological performances for CrAlCN nanocomposite coating in the seawater

Abstract

Electrochemical corrosion and wear frequently rise some fatal failures of metallic components in the seawater, so it is of significance to explore a protective coating for them. In this study, the multilayer interfacial Cr/CrAlCN nanocomposite coating is successfully fabricated by the multi-arc ion technique, and its microstructures, corrosion and tribological performances are investigated systematically. Results show that as-prepared Cr/CrAlCN multilayer coating with an alternating multi-interfacial microstructure efficiently prevents from the growth of columnar crystals so as to enhance its compactness, and especially it exhibits much higher hardness (32.5 GPa) and elastic modulus (327.8 GPa), better toughness and adhesion strength (24.1 N) compared to CrAlCN monolayer coating. Also, this multi-interfacial design profitably reduces the porosities and forms an interval labyrinth effect, which effectively blocks the corrosive mediums. As a result, this Cr/CrAlCN nanocomposite coating achieves excellent anti-corrosion (Icorr: 6.3 × 10−6 A/cm2) and tribological performances (seawater wear rate of 3.5 × 10−6 mm3 N−1 m−1), which demonstrates its promising application as a protective coating in the seawater.