In a method, an aluminum body is chemically treated with at least one of an alkaline solution and an acid solution. Anode-oxidization is performed on the chemically treated aluminum body to form an aluminum oxide layer. The aluminum oxide layer is treated with hot water at a temperature more than 75° C. or steam. The aluminum oxide layer after being treated with hot water or steam includes plural columnar grains, and an average width of the columnar grains is in a range from 10 nm to 100 nm.

An aluminum member (1) includes: a base material (2) composed of aluminum or an aluminum alloy; and an anodic oxide film (3) formed on a surface of the base material. The anodic oxide film includes: an amorphous layer (31), which is composed of an amorphous aluminum oxide and is formed on the base material (2); and a crystal layer (32), which is composed of a crystalline aluminum oxide and is formed on the amorphous layer (31). The aluminum member (1) can be obtained by forming the anodic oxide film (3) on the base material (2) by performing an anodization process on the base material (2) in an electrolytic solution, which contains boron atoms and has a pH of 7.0-12.0.

Anodic oxide coatings that provide corrosion resistance to parts having protruding features, such as edges, corners and convex-shaped features, are described. According to some embodiments, the anodic oxide coatings include an inner porous layer and an outer porous layer. The inner layer is adjacent to an underlying metal substrate and is formed under compressive stress anodizing conditions that allow the inner porous layer to be formed generally crack-free. In this way, the inner porous layer acts as a barrier that prevents water or other corrosion-inducing agents from reaching the underlying metal substrate. The outer porous layer can be thicker and harder than the inner porous layer, thereby increasing the overall hardness of the anodic oxide coating.

Anodic oxide coatings that provide corrosion resistance to parts having protruding features, such as edges, corners and convex-shaped features, are described. According to some embodiments, the anodic oxide coatings include an inner porous layer and an outer porous layer. The inner layer is adjacent to an underlying metal substrate and is formed under compressive stress anodizing conditions that allow the inner porous layer to be formed generally crack-free. In this way, the inner porous layer acts as a barrier that prevents water or other corrosion-inducing agents from reaching the underlying metal substrate. The outer porous layer can be thicker and harder than the inner porous layer, thereby increasing the overall hardness of the anodic oxide coating.

The present disclosure relates to an aluminum member including a mother material containing aluminum or an aluminum alloy, and an anodic oxide film on the surface of the mother material. The anodic oxide film has a barrier layer on the surface of the mother material, and a porous layer on the barrier layer), and the BET specific surface area of the anodic oxide film is 0.1 to 10.0 m.sup.2/g.

The present disclosure relates to an aluminum member including a mother material containing aluminum or an aluminum alloy, and an anodic oxide film on the surface of the mother material. The anodic oxide film has a barrier layer on the surface of the mother material, and a porous layer on the barrier layer), and the BET specific surface area of the anodic oxide film is 0.1 to 10.0 m.sup.2/g.

This application relates to a multi-piece enclosure for a portable electronic device. The enclosure includes a metal part including a metal substrate and a metal oxide layer overlaying the metal substrate, the metal oxide layer having an external surface that includes openings that lead into undercut regions. The openings are characterized as having a first width, and the undercut regions are characterized as having a second width that is greater than the first width. The enclosure further includes a non-metallic bulk layer including protruding portions that extend into the undercut regions such that the non-metallic bulk layer is interlocked with the metal part.

This application relates to a multi-piece enclosure for a portable electronic device. The enclosure includes a metal part including a metal substrate and a metal oxide layer overlaying the metal substrate, the metal oxide layer having an external surface that includes openings that lead into undercut regions. The openings are characterized as having a first width, and the undercut regions are characterized as having a second width that is greater than the first width. The enclosure further includes a non-metallic bulk layer including protruding portions that extend into the undercut regions such that the non-metallic bulk layer is interlocked with the metal part.

The present disclosure relates to an electrode for eloxing a component, in particular a component of a vehicle brake system, comprising an electrolyte inlet for feeding an electrolyte into the electrode, an inlet channel, which connects the electrolyte inlet to an electrolyte outlet opening formed in the region of an outer surface of the electrode, an electrolyte inlet opening formed in the region of the outer surface of the electrode at a distance from the electrolyte outlet opening, an electrolyte flow path, which runs between the electrolyte outlet opening and the electrolyte inlet opening along the outer surface of the electrode and is designed to bring a surface portion of the component, which surface portion is to be eloxed, into fluid contact with the electrolyte flowing through the electrolyte flow path, an outlet channel, and an electrolyte outlet.

The present disclosure relates to an electrode for eloxing a component, in particular a component of a vehicle brake system, comprising an electrolyte inlet for feeding an electrolyte into the electrode, an inlet channel, which connects the electrolyte inlet to an electrolyte outlet opening formed in the region of an outer surface of the electrode, an electrolyte inlet opening formed in the region of the outer surface of the electrode at a distance from the electrolyte outlet opening, an electrolyte flow path, which runs between the electrolyte outlet opening and the electrolyte inlet opening along the outer surface of the electrode and is designed to bring a surface portion of the component, which surface portion is to be eloxed, into fluid contact with the electrolyte flowing through the electrolyte flow path, an outlet channel, and an electrolyte outlet.