Improving anti-wear and anti-corrosion properties of AM60 magnesium alloy by ion implantation and Al/AlN/CrAlN/CrN/MoS2 gradient duplex coating

A novel ion implantation and Al/AlN/CrAlN/CrN/MoS2 gradient duplex coating was used to improve the wear-corrosion synergy performance of AM60 magnesium alloy. The wear and corrosion behaviors of the as-deposited gradient duplex coating were subsequently investigated. The results showed that the gradient duplex coating has excellent wear resistance with the wear rate of 2.31 × 10−6 mm3/Nm, which is far below compared to that of the uncoated magnesium alloy of about 3.15 × 10−4 mm3/Nm. The introduction of intermediate layers between the top MoS2 layer and magnesium alloy substrate remarkably improved the magnesium alloy's load bearing capacity. The hardness and modulus of the Al/AlN/CrAlN/CrN intermediate layer was 20 and 7 times larger than that of the uncoated magnesium alloy, respectively. In addition, the corrosion resistance of the magnesium alloy with the gradient duplex coating was also enhanced with the corrosion current density, which decreased from 1.25 × 10−5 A/cm2 to 6.19 × 10−7 A/cm2. The present work provided a feasible strategy to fabricate wear-corrosion resistant coating via component and structure gradient design.