Aluminum foils were dipped in solution containing Ti~(4+) and heated in air at 500℃ to deposit Ti oxide on the inner walls
of pores,and then anodized galvanostatically in ammonium adipate solution,by which Al-Ti composite oxide films were achieved.Film composition and percentage of atom were analyzed by XPS,voltage-time response of
aluminum foil during anodizing was followed,dielectric constant of composite films was calculated in theory,and capacitance and durability of aluminum electrolytic capacitors was examined.The results show that impregnating time is optimally 10min,and compared with pure aluminum foils,aluminum foils after impregnating present a larger anodizing velocity.At the same withstanding voltage,the electric capacitance of aluminum electrolytic capacitors with Al-Ti composite oxide films is about 23% higher than that with pure Al_2O_3 film.The theoretical calculation of dielectric constant is in good agreement with experimental result.The Al-Ti composite oxide films are suitable for dielectric of aluminum electrolytic capacitors.