Effect of Preparation Conditions on the Performance of Anodic Aluminum Oxide Films

Neodymium salt was used as additives in preparing anodic aluminum oxide (AAO) films to improve its performance. AAO films were prepared by anodization method from a 15 vol. % sulphuric acid solution containing neodymium salt. The effects of anodization voltage, anodization temperature and anodization time on microhardness and thickness of AAO films were researched, respectively. The thickness of AAO film increases with the increase of anodization voltage, the microhardness of AAO film decreases with the increase of anodization voltage in 19 V～23 V. The thickness of AAO film increases with the increase of anodization temperature, the microhardness of AAO film decreases with the increase of anodization temperature in 11 °C～19°C. The thickness of AAO film increases with the increase of anodization time, the microhardness of AAO film decreases with the increase of anodization time in 30 min～3 h. When the anodizing parameters: anodization voltage: 22 V, temperature: 15°C, anodization time: 2 h, the thickness and microhardness of AAO film is as high as 135μm and 305.4 HV.