US 8,282,807 B2 · Metal member having a metal oxide film and method of manufacturing the same

Abstract

In a method of manufacturing a metal member, a metal material containing aluminum as a main component is anodized in an anodization solution having a pH of 4 to 10 and containing a nonaqueous solvent having a dielectric constant smaller than that of water and capable of dissolving water, thereby forming a nonporous amorphous aluminum oxide passivation film on a surface of the metal member. The method includes a step of controlling the viscosity of the anodization solution. In the step of controlling the viscosity, the viscosity of the anodization solution is lowered by elevating the temperature of the anodization solution above the room temperature or by adding to the anodization solution a substance having a dielectric constant smaller than that of water and a viscosity lower than that of the nonaqueous solvent.

Claims24

Dependent claims

A method of manufacturing a metal member comprising:

(A) anodizing a metal material comprising 50 wt. % or more aluminum and 1 to 4.5 wt. % magnesium in an anodization solution having a pH of 4 to 10 and comprising a nonaqueous solvent having a dielectric constant smaller than that of water and capable of dissolving water, the nonaqueous solvent comprising at least one selected from the group consisting of diethylene glycol, triethylene glycol, and tetraethylene glycol;
(B) controlling viscosity of the anodization solution which comprises maintaining the anodization solution at a temperature within a range between 30° C. and 70° C.;
and
thereby forming a nonporous amorphous aluminum oxide passivation film on a surface of the metal material.

1 more element

Dependencies are inferred from the claim text.

Metal member having a metal oxide film and method of manufacturing the same

Life of this patent

Metal member having a metal oxide film and method of manufacturing the same

Life of this patent

Abstract

Claims24