Al 2O 3 coatings were fabricated on 2024 aluminum alloy thin sheets via constant and step potential anodization to enhance surface performance. In the step potential mode, the voltage was sequentially increased from 14   V to 22, 26, 30, and 34   V, with each intermediate step maintained for 10   minutes. The final potential step was extended to ensure a total anodizing time of 60   minutes. A series of fixed potentials (22, 26, 30, and 34   V) was also applied under constant potential for comparison. The coatings were comprehensively characterized in terms of microstructure, hardness, electrochemical response, tribological behavior, and tensile properties. Under constant potential, coatings exhibited microcracking and a maximum barrier layer thickness of 35.85   nm at 30   V, corresponding to a hardness of 295 HV. In contrast, the coating formed at 30   V under step potential showed a denser structure, with a barrier layer thickness of 38.79   nm and a hardness of 325 HV. Among all conditions, the step potential coating at 30   V demonstrated the best corrosion resistance, with a corrosion potential ( E corr) of −0.641   V, a corrosion current density ( I corr) of 1.219 μA·cm⁻ 2, and a wear volume of 0.089   mm³. Tensile testing revealed that Al 2O 3 coatings reduced the substrate’s tensile strength and elongation, with smaller reductions under step potential. Specifically, at 30   V, tensile strength decreased by 46.9   MPa and elongation by 0.06%. These results demonstrate that step potential anodization at 30   V yields a denser Al 2O 3 coating with enhanced corrosion and wear resistance, while better preserving the mechanical properties compared to constant potential.