Method for formation of anode oxide film

摘要

The present invention provides a method for forming an anode oxide film, in which on the assumption that a direct-current power source is used, a thick anode oxide film can be formed with good productivity within a short time without using special equipment. The method includes allowing a current A0 to pass through an aluminum base material, and includes a step of repeating a first electricity cut-off treatment multiple times, in which when a voltage reaches a voltage V1 during the formation of the film, the passage of electricity is once cut off, this electricity cut-off is continued for a period equal to or longer than an electricity cut-off time T1, and the passage of electricity is then resumed, wherein the voltage V1 and electricity cut-off time T1 satisfy the prescribed expressions.

主权项

1. A method for forming an anode oxide film on an aluminum base material, the method comprising
passing a prescribed current A0 through the aluminum base material which is aluminum or an aluminum alloy, repeating a first electricity cut-off treatment multiple times, in which when a voltage reaches a prescribed voltage V1 during formation of the film, passage of electricity is once cut off, remains cut off for a period equal to or longer than an electricity cut-off time T1, and is then resumed, and conducting a second electricity cut-off treatment in which an electricity cut-off time is longer than the electricity cut-off time T1, wherein the prescribed voltage V1 satisfies expression (1a); the electricity cut-off time T1 satisfies expression (1b); and said conducting occurs after the first electricity cut-off treatment at the n-th time which satisfies expression (3):
V1