Enhanced corrosion and tribo-corrosion resistance of self-organized nano-multilayer oxynitride coatings on tungsten copper alloy

Surface protective coating is crucial for tungsten-copper alloys to prevent corrosion failure in marine applications. In this work, self-organized nanomultilayer AlCrON coatings with alternating nitrogen-rich and oxygen-rich sublayers were fabricated by arc ion plating technology, whose modulation structure was adjusted by altering substrate-rotation mode. AlCrON deposited with 2D rotation exhibits minimum modulation period and superior protective effect in electrochemical, acidic-salt-spray corrosion and tribo-corrosion conditions. No obvious corrosion was observed on AlCrON coated tungsten-copper alloy after acidic-salt-spray exposure for 180 h. Oxygen doping and nano-multilayer interfaces effectively restrained galvanic corrosion, blocked the intrusion of corrosive media and enhanced the corrosion resistance.