In the present study, the TiO2-graphene surface coating was prepared by electrophoretic deposition (EPD) on the AZ91D Mg alloy. The Taguchi method was used to optimize the parameters, including heat-treatment temperature, graphene addition, and EPD voltage. With the optimal parameter combination, the surface-treated sample exhibited a corrosion current density of 7.33 µA/cm2 and a corrosion rate of 0.82 mpy, both significantly lower than those of the uncoated AZ91D alloy (41.30 µA/cm2 and 2.85 mpy, respectively), indicating a substantial improvement in corrosion resistance. Furthermore, wear tests and microhardness measurements showed that the treated surface exhibited approximately a 64% reduction in friction coefficient and a 44% increase in hardness compared to the untreated base material. The results demonstrate that surface modification of AZ91D magnesium alloy via electrophoretic deposition can effectively enhance corrosion and wear resistance.
Chiu et al. (Wed,) studied this question.