Corrosion behavior of carbon film coated magnesium alloy with electroless plating nickel interlayer

The carbon film with electroless nickel interlayer (Ni + C) was fabricated to improve the corrosion resistance of the magnesium alloy GW83. Compared to other coatings used in this study, the dense Ni + C coating improved adhesion with the substrate. The corrosion potential (Ecorr) of the Ni + C coated magnesium alloy was about −1.37 V vs saturated calomel electrode (SCE) in contrast to about −1.67 V vs SCE of the bare one in 3.5 wt% NaCl solution. The corrosion current density was reduced from 186 μA cm−2 to 11 μA cm−2. The 5 h immersion test revealed that the Ni + C coated magnesium alloy GW83 showed much less corrosion compared to the bare alloy. These evidences indicated that applying Ni + C coating could effectively improve the corrosion resistance of the magnesium alloy GW83.