抄録
The anodization of aluminum was investigated in 15w/v% sulfuric acid baths in which were dispersed ferromagnetic metal oxides (CrO2, Fe3O4), with and without a magnetic field.
Anodization was carried out at a constant current density of 2A/dm2 and at bath temperature of 5-30°C.
Electrolysis time was 30 minutes.
It was found that both the thickness and hardness of the films were increased over the usually hard anodic coating of aluminum in the presence of Fe3O4 or CrO2 under magnetic field.
The use of TiO2, which unmagnetized metal oxide, however resulted in no difference.
The effect on film thickness and hardness increased in order of Fe3O4>CrO2.
Optimum conditions were with 5% Fe3O4, magnetic field as large as possible, and a bath temperature of about 5°C.
