Suzuki Motor Corporation

Hiroomi Tanaka

Tomoharu Yamamoto

Masahiro Fujita

An anodizing method in which a workpiece made of aluminum or aluminum alloy is immersed in an electrolytic solution, and treatment is performed in which the application of positive voltage for a very short period of time and the removal of charges are repeated alternately between the workpiece and a cathode arranged in the electrolytic solution includes a step of performing treatment in which the positive voltage application and the charge removal are repeated in a tentative cycle, measuring the control point arrival time of a current waveform at the positive voltage application period, and determining normal positive voltage application time based on the control point arrival time; and a step of performing treatment in which the application of positive voltage and the removal of charges are repeated in a cycle corresponding to the normal positive voltage application time, and forming an anodized film on the surface of the workpiece.

Anodizing method and apparatus

An anodizing apparatus for forming an anodized film on the surface of a workpiece () made of aluminum or aluminum alloy includes a treatment tank () for containing an electrolytic solution, a cathode plate () disposed in the treatment tank, a supporting means () for supporting the workpiece so as to be immersed in the electrolytic solution, and a power supply () for continuously or intermittently applying a short-period bipolar or unipolar pulse voltage or an alternating voltage to between the workpiece and the cathode plate. The cathode plate () is arranged in a crosswise direction with respect to the workpiece ().

Anodizing apparatus

An object of the present invention is to obtain an aluminum or aluminum alloy member having a uniform and dense anodic oxide film having sufficient corrosion and impact resistances. Provided is an anodic oxide film which has been formed on the surface of aluminum or aluminum alloy, the film comprising cells which have grown in random directions relative to the surface of the aluminum or aluminum alloy and thus have no orientation.

Growing community of inventors

Shizuoka-ken, Japan

Hiroomi Tanaka