A hearth roll includes a base roll, a thermally sprayed coating formed on the base roll, and a modified coating formed on the thermally sprayed coating. The modified coating is formed by modifying a part or the whole of a surface of the thermally sprayed coating by melting and solidification of the thermally sprayed coating, by irradiating a part or the whole of the surface of the thermally sprayed coating with an energy beam. The thickness of the modified coating is from 2 to 20 m, and the Vickers hardness HV of the modified coating is from 1.2 to 1.4 times larger than the Vickers hardness HV of the thermally sprayed coating.

A titanium or titanium alloy material for a separator of a polymer electrolyte fuel cell having high contact conductivity with carbon and high durability, and including an oxide film formed on a titanium or titanium alloy substrate by a stabilization treatment performed after a passivation treatment, and one or more kinds of conductive materials selected from carbide, nitride, carbonitride, and boride of tantalum, titanium, vanadium, zirconium, and chromium, the conductive materials being dispersed in the oxide film and having a major axis diameter of from 1 nm to 100 nm. A contact resistance value with a carbon paper is 20 m.Math.cm.sup.2 or less at a surface pressure of 10 kgf/cm.sup.2 before and after an accelerated deterioration test in which the titanium or titanium alloy material is immersed in a sulfuric acid aqueous solution having an adjusted pH of 4 at 80 C. for four days.

A titanium or titanium alloy material for a separator of a polymer electrolyte fuel cell having high contact conductivity with carbon and high durability, and including an oxide film formed on a titanium or titanium alloy substrate by a stabilization treatment performed after a passivation treatment, and one or more kinds of conductive materials selected from carbide, nitride, carbonitride, and boride of tantalum, titanium, vanadium, zirconium, and chromium, the conductive materials being dispersed in the oxide film and having a major axis diameter of from 1 nm to 100 nm. A contact resistance value with a carbon paper is 20 m.Math.cm.sup.2 or less at a surface pressure of 10 kgf/cm.sup.2 before and after an accelerated deterioration test in which the titanium or titanium alloy material is immersed in a sulfuric acid aqueous solution having an adjusted pH of 4 at 80 C. for four days.

This surface-treated copper foil is characterized in that the amount of adhesion of Si on the copper foil surface is from 3.1 to 300 g/dm.sup.2, and the amount of adhesion of N on the copper foil surface is from 2.5 to 690 g/dm.sup.2. The objective of the present invention is to obtain a copper foil having improved peel strength in providing a copper foil for a flexible printed substrate (FPC), in which a copper foil is laminated to a liquid crystal polymer (LCP) suitable for high-frequency applications.

This surface-treated copper foil is characterized in that the amount of adhesion of Si on the copper foil surface is from 3.1 to 300 g/dm.sup.2, and the amount of adhesion of N on the copper foil surface is from 2.5 to 690 g/dm.sup.2. The objective of the present invention is to obtain a copper foil having improved peel strength in providing a copper foil for a flexible printed substrate (FPC), in which a copper foil is laminated to a liquid crystal polymer (LCP) suitable for high-frequency applications.

To provide a surface-treated copper foil that can favorably decrease the transmission loss even used in a high frequency circuit board, and has improved acid resistance. A surface-treated copper foil containing a copper foil, and a surface treatment layer containing a roughening treatment layer on at least one surface of the copper foil, wherein the surface treatment layer contains Ni, the surface treatment layer has a content ratio of Ni of 8% by mass or less (excluding 0% by mass), and an outermost surface of the surface treatment layer has a ten-point average roughness Rz of 1.4 m or less.

A method of spray coating a surface having a magnesium base is provided. The method includes, in sequence, applying a magnesium oxidizing agent onto the surface; determining whether an entirety of the surface has oxidized as a result of applying the magnesium oxidizing agent onto the surface; and spray coating the surface.

A method of spray coating a surface having a magnesium base is provided. The method includes, in sequence, applying a magnesium oxidizing agent onto the surface; determining whether an entirety of the surface has oxidized as a result of applying the magnesium oxidizing agent onto the surface; and spray coating the surface.

A method for manufacturing a cover member for electronic devices according to certain embodiments of the present disclosure may comprise: a step for forming a magnesium plate; a step for performing primary CNC processing on the magnesium plate using a predetermined cutting oil; a step for performing a primary pretreatment on the magnesium plate using chromate or micro arc oxidation (MAO); a step for performing a primary surface-treatment on the magnesium plate by bake-coating or electrodeposition coating; a step for performing secondary CNC processing on a first region of the magnesium plate using an alcohol-containing cutting oil; a washing and drying step; a step for performing a secondary pretreatment for preventing oxidation on the first region; and a step for performing a secondary surface-treatment on the first region by bake-coating or electrodeposition coating.

The invention concerns a method for manufacturing a process apparatus for moving liquid in high temperature liquid immersion under aggressive chemical environment and dynamic stress, wherein the method comprises the step of lining the process apparatus formed of stainless steel with rubber, wherein the method further comprises the step of forming a passivation layer on a surface of the process apparatus in an acid bath prior to lining the process apparatus comprising the passivation layer with rubber. The invention also concerns a process apparatus.