Effect of Graphene Oxide Addition on the Behavior of Tribological Properties of Coatings Prepared on Magnesium Alloy AZ31 by Plasma Electrolytic Oxidation Method

In this study, the effect of adding graphene oxide on the terbiological behavior of coatings created by the electrolytic plasma oxidation process under constant voltage conditions has been investigated. Bipolar waveform coating operation was performed on the surface of AZ31 magnesium alloy for 10 minutes. The results showed that the surface morphology of the coatings had micro-cavities known as pancake structure and volcanic crater on the surface, the diameter of which increased with the addition of graphene oxide. Fuzzy analysis of coatings showed that the coatings are composed of oxide phases of forsterite and periclase. The wear mechanism of the coated samples was scratched. Also, the wear resistance of the coating containing graphene oxide additive increased so that the average coefficient of friction for the mentioned samples decreased 10 times compared to the uncoated sample, which is due to the increase in hardness. The hardness of the sample containing graphene oxide has increased about 5 times compared to the magnesium alloy. Magnesium alloy with this coating is a good candidate for orthopedic applications.