抄録
The objective of this study was to form a crystalline oxide film on an aluminum substrate using micro-arc oxidation (MAO) processing at half-wave rectification current. A crystalline oxide film was able to be formed on an aluminum substrate using this method. It was found that the electrolytic aqueous solution selectivity, discharge condition, oxide film surface condition and reaction mechanism observed in MAO-processing at half-wave rectification current were different from those observed in MAO-processing using a direct current. The electrolytic aqueous solution selectivity range was small, and in many instances a small discharge appeared during MAO-processing at half-wave rectification current. Furthermore, the surface of the film was generally smooth and contained small pores. Combining both of the MAO-processing was possible, with the result that the condition of the film surface was significantly influenced by the second step MAO-processing.
