Research on Effect of Erbium Salt in the Anodization of Aluminum

Abstract

Erbium salt was used as additives for the first time in preparing anodic aluminum oxide (AAO) films to improve its performance. AAO films were prepared from a 15 vol. % sulphuric acid solution containing erbium salt by anodization method; the effects of concentration of erbium on microhardness and thickness of AAO film were researched, respectively. The effect of heat treatment temperature on structure of AAO film was researched. AAO films were characterized by XRD, EDAX and SEM techniques, respectively. The microhardness and thickness of AAO film were 378.5HV and 82μm respectively, which were higher 12.99% and 17.14% than those of the film prepared in electrolyte of nothing addition erbium salt respectively. The aperture of AAO film was more uniform and the surface of AAO film was smoother than those of films prepared in electrolyte of nothing addition erbium salt. The apertures of AAO film were in 25~30nm. There was not erbium in AAO film. AAO films were amorphous when heat treatment temperatures of AAO film were below 800°C, when heat treatment temperature of AAO film were 850°C and 1000°C respectively, and AAO films were γ-Al2O3and α-Al2O3film respectively.