Abstract:To enhance the comprehensive performance of magnesium alloy surfaces, Ni-based composite layers added with zero-dimensional material nano-diamond (ND) and one-dimensional material carbon nanotubes (CNTs) were prepared on the surface of AZ91D magnesium alloy by nano-composite electrodeposition technique. The results show that the synergistic effect of the combination of ND and CNTs optimizes the microstructure of the deposited layer and enhances its comprehensive performance. ND, as a heterogeneous nucleation core, promotes the preferred orientation growth of Ni grains along the (111) plane, reduces the surface roughness of Ni-based deposition layers, and enhances their microstructure uniformity and density. The high specific surface area and excellent electrical conductivity of CNTs further optimize the microstructure and properties of the deposited layer. The combination of two carbon-based nanomaterials exhibits an excellent synergistic effect: the grain refinement effect of ND and the electrical conductivity enhancement effect of CNTs complement each other, significantly optimizing the deposited layer in terms of structural density, grain orientation stability, and interfacial bonding strength, further enhancing wear resistance and corrosion resistance. When the addition amounts of ND and CNTs are 12 and 0.15 g/L, respectively, the microstructure of the deposited layer is uniform and dense, the hardness reaches 1212.7 HV, the coefficient of friction decreases to 0.34, the self-corrosion current density decreases to 1.458×10?7 A·cm?2 (three orders of magnitude lower than that of the magnesium alloy matrix), and the resistance to Pseudomonas aeruginosa is good. The antibacterial rate is as high as 90%. This study provides a theoretical basis and process reference for the synergistic reinforcement of composite deposition layers on high-performance magnesium alloy surface with low-dimensional materials.