There is provided a surface-treated steel sheet (1) comprising: a tin-plated steel sheet (10) obtained by tin-plating a steel sheet (11); a phosphate compound layer (20) containing tin phosphate formed on the tin-plated steel sheet (10); and an aluminum-oxygen compound layer (30) on the phosphate compound layer (20), a main constituent of the aluminum-oxygen compound layer (30) being an aluminum-oxygen compound; wherein, when the 3d.sub.5/2 spectrum of tin in the aluminum-oxygen compound layer (30) is determined using an X-ray photoelectron spectroscopy, the ratio of the integration value of the profile derived from tin oxide to the integration value of the profile derived from tin phosphate (tin oxide/tin phosphate) is 6.9 or more.

A method of preparing a modified-metal surface. The method includes preparing a solution of a phosphorous-based acid in a solvent; immersing a strip of the metal work piece into the solution of the phosphorous-based acid; immersing a strip of a reference metal into the solution of the phosphorous-based acid; supplying a voltage for a duration of time to prepare a phosphorous acid-modified metal work piece; removing the phosphorous acid-modified metal work piece; cleaning and drying the phosphorous acid-modified metal work piece; applying a chitosan solution to the surface in order to attach chitosan/modified chitosan to the phosphorous acid based modified surface; prepare the modified-metal surface; and cleaning and drying the modified-metal surface.

A method of preparing a modified-metal surface. The method includes preparing a solution of a phosphorous-based acid in a solvent; immersing a strip of the metal work piece into the solution of the phosphorous-based acid; immersing a strip of a reference metal into the solution of the phosphorous-based acid; supplying a voltage for a duration of time to prepare a phosphorous acid-modified metal work piece; removing the phosphorous acid-modified metal work piece; cleaning and drying the phosphorous acid-modified metal work piece; applying a chitosan solution to the surface in order to attach chitosan/modified chitosan to the phosphorous acid based modified surface; prepare the modified-metal surface; and cleaning and drying the modified-metal surface.

A method of preparing a modified-metal surface. The method includes preparing a solution of a phosphorous-based acid in a solvent; immersing a strip of the metal work piece into the solution of the phosphorous-based acid; immersing a strip of a reference metal into the solution of the phosphorous-based acid; supplying a voltage for a duration of time to prepare a phosphorous acid-modified metal work piece; removing the phosphorous acid-modified metal work piece; cleaning and drying the phosphorous acid-modified metal work piece; applying a chitosan solution to the surface in order to attach chitosan/modified chitosan to the phosphorous acid based modified surface; prepare the modified-metal surface; and cleaning and drying the modified-metal surface.

A method of preparing a modified-metal surface. The method includes preparing a solution of a phosphorous-based acid in a solvent; immersing a strip of the metal work piece into the solution of the phosphorous-based acid; immersing a strip of a reference metal into the solution of the phosphorous-based acid; supplying a voltage for a duration of time to prepare a phosphorous acid-modified metal work piece; removing the phosphorous acid-modified metal work piece; cleaning and drying the phosphorous acid-modified metal work piece; applying a chitosan solution to the surface in order to attach chitosan/modified chitosan to the phosphorous acid based modified surface; prepare the modified-metal surface; and cleaning and drying the modified-metal surface.

A method and apparatus for processing an object (4), for example an aluminium aircraft part, the method comprising: performing a first conversion coating process to dispose a first conversion coating (10) onto at least part of a surface of the object (4); partially masking the first conversion coating (10) disposed on the object (4); performing an etching process to remove, from the object (4), an unmasked portion of the first conversion coating (10) while retaining the masked portion of the first conversion coating (10) on the object (4); and performing a second conversion coating process to dispose a second conversion coating (12) onto a region of the surface of the object (4) from which the unmasked portion of the first conversion coating (10) was removed. A paint layer (14) may then be applied to, e.g., the second conversion coating (12).

A material, such as a flexible sheet, including a metal or metal alloy, wherein the metal or metal alloy has at least one porous metal oxide layer thereon. In some examples, the at least one metal oxide layer has a three-dimensional disordered network of channels in which the pores have non-constant diameters. Methods of preparing the materials are also disclosed.

Provided is a chemical treatment steel sheet including a steel sheet; a composite coated layer which is formed on at least one surface of the steel sheet, and contains 2 to 200 mg/m.sup.2 of Ni in terms of an amount of metal Ni and 0.1 to 10 g/m.sup.2 of Sn in terms of an amount of metal Sn, and in which an island-shaped Sn coated layer is formed on an Fe—Ni—Sn alloy layer; and a chemical treatment layer that is formed on the composite coated layer, and contains a 0.01 to 0.1 mg/m.sup.2 of Zr compounds in terms of an amount of metal Zr and 0.01 to 5 mg/m.sup.2 of phosphate compounds in terms of an amount of P.

The present disclosure provides a method of manufacturing a surface nanotube array of a laser-melted stainless steel, including a step of an anodic oxidation treatment on the stainless steel, which includes performing the anodic oxidation treatment on the stainless steel by applying a voltage between the stainless steel as an anode and a graphite as a cathode in a solution formed by using sodium dihydrogen phosphate, perchloric acid, and ethylene glycol as a solute, and deionized water as a solvent.

A method of preparing a modified-metal surface by attaching a phosphorous-based acid to a surface of a metal: preparing a solution of the phosphorous-based acid in a protic solvent; immersing a strip of a metal work piece into the solution of the phosphorous-based acid, immersing a strip of a reference metal into the solution of the phosphorous-based acid, supplying a voltage for a duration of time, removing the metal work piece, cleaning the metal work piece, and drying the cleaned metal work piece under an inert atmosphere to obtain a modified metal work piece.