Corrosion resistance of AlN monolayer and Al/AlN multilayer deposited by filtered cathodic vacuum arc

The AlN monolayer and (Al/AlN)5 multilayer coatings were deposited on AZ31 magnesium alloys by filtered cathodic vacuum arc technology. The AlN monolayer showed a dense structure, but there were some holes at the coating/substrate interface. The (Al/AlN)5 multilayer showed a compact layered structure and the holes were interrupted by the Al/AlN interface. Both AlN monolayer and (Al/AlN)5 multilayer provided excellent corrosion resistance for magnesium alloys, with low corrosion current density of 1.91 x 10-6 and 1.11 x 10-6 A/cm2 , respectively. Better corrosion resistance of the (Al/AlN)5 multilayer is attributed to its denser layered structure, better adhesion strength, better crack propagation resistance, and deformation coordination between coating and substrate during corrosion.

Automated summary

The AlN monolayer and (Al/AlN)5 multilayer coatings were deposited on AZ31 magnesium alloys using filtered cathodic vacuum arc technology. The AlN monolayer had a dense structure with some holes at the coating/substrate interface. The (Al/AlN)5 multilayer exhibited a compact layered structure with interrupted holes by the Al/AlN interface. Both AlN monolayer and (Al/AlN)5 multilayer showed excellent corrosion resistance, with low corrosion current densities of 1.91 x 10-6 and 1.11 x 10-6 A/cm2 respectively. The improved corrosion resistance of the (Al/AlN)5 multilayer can be attributed to its denser layered structure, better adhesion strength, crack propagation resistance, and deformation coordination between coating and substrate during corrosion.