A sliding member includes, on a surface of a metal substrate, a surface-treated layer including a zinc-electroplated layer, a chemical conversion-treated layer, and a topcoat layer sequentially stacked on the metal substrate. The chemical conversion-treated layer includes chromium and oxygen. The topcoat layer includes at least one material selected from the group consisting of a silica compound, acrylic resin, polyurethane resin, epoxy resin, phenol resin, and melamine resin. A method of manufacturing the sliding member includes a step of forming, on a surface of the chemical conversion-treated layer, the topcoat layer including at least one material selected from the group consisting of a silica compound, acrylic resin, polyurethane resin, epoxy resin, phenol resin, and melamine resin.

A trivalent-chromium chemical conversion coating from which substantially no hexavalent chromium is released. The trivalent-chromium chemical conversion coating is one formed on the surface of a zinc or zinc-alloy deposit. In a brine spray test, the chemical conversion coating has unsusceptibility to corrosion (time required for white-rust formation) of 96 hours or longer. The chemical conversion coating has a hexavalent-chromium concentration less than 0.01 μg/cm.sup.2 in terms of metal atom amount. The amount of hexavalent chromium released after 30-day standing in a thermo-hygrostatic chamber at a temperature of 80° C. and a humidity of 95% (amount of hexavalent chromium released when the coating is immersed in 100° C. water for 10 minutes) is smaller than 0.05 μg/cm.sup.2.

A trivalent-chromium chemical conversion coating from which substantially no hexavalent chromium is released. The trivalent-chromium chemical conversion coating is one formed on the surface of a zinc or zinc-alloy deposit. In a brine spray test, the chemical conversion coating has unsusceptibility to corrosion (time required for white-rust formation) of 96 hours or longer. The chemical conversion coating has a hexavalent-chromium concentration less than 0.01 μg/cm.sup.2 in terms of metal atom amount. The amount of hexavalent chromium released after 30-day standing in a thermo-hygrostatic chamber at a temperature of 80° C. and a humidity of 95% (amount of hexavalent chromium released when the coating is immersed in 100° C. water for 10 minutes) is smaller than 0.05 μg/cm.sup.2.

Disclosed is a system for treating a surface of a multi-metal article. The system includes first and second and/or third conversion compositions for contacting at least a portion of the surface. The first conversion composition includes phosphate ions and zinc ions and is substantially free of fluoride. The second conversion composition includes a lanthanide series metal cation and an oxidizing agent. The third conversion composition includes an organophosphate compound, an organophosphonate compound, or combinations thereof that optionally may include at least one transition metal. Methods of treating a multi-metal article using the system also are disclosed. Also disclosed are substrates treated with the system and method.

Disclosed is a system for treating a surface of a multi-metal article. The system includes first and second and/or third conversion compositions for contacting at least a portion of the surface. The first conversion composition includes phosphate ions and zinc ions and is substantially free of fluoride. The second conversion composition includes a lanthanide series metal cation and an oxidizing agent. The third conversion composition includes an organophosphate compound, an organophosphonate compound, or combinations thereof that optionally may include at least one transition metal. Methods of treating a multi-metal article using the system also are disclosed. Also disclosed are substrates treated with the system and method.

A method to treat the magnesium surface to manufacture the metallic assembly with the polymer and magnesium to have excellent bonding strength is disclosed. As a method to treat the magnesium surface for the bonded coupling of the mixture of the polymer and magnesium, this is a method including, (a) an etching step, wherein the magnesium surface is treated with an acidic solution; (b) a first surface treatment step, wherein the magnesium surface is treated with ultrasonic waves; (c) a second surface treatment step, wherein the magnesium surface is treated with an acidic solution; (d) a first silane coupling processing step, wherein the magnesium surface is treated with ultrasonic waves; (e) a surface activation treatment step, wherein the magnesium surface is treated with acidic solution; and (f) a second silane coupling processing step, wherein the magnesium surface is treated with ultrasonic waves.

A method to treat the magnesium surface to manufacture the metallic assembly with the polymer and magnesium to have excellent bonding strength is disclosed. As a method to treat the magnesium surface for the bonded coupling of the mixture of the polymer and magnesium, this is a method including, (a) an etching step, wherein the magnesium surface is treated with an acidic solution; (b) a first surface treatment step, wherein the magnesium surface is treated with ultrasonic waves; (c) a second surface treatment step, wherein the magnesium surface is treated with an acidic solution; (d) a first silane coupling processing step, wherein the magnesium surface is treated with ultrasonic waves; (e) a surface activation treatment step, wherein the magnesium surface is treated with acidic solution; and (f) a second silane coupling processing step, wherein the magnesium surface is treated with ultrasonic waves.

The invention relates generally to liquid-repellent coatings, and in particular, to porous liquid-repellent coatings, a method of preparing the porous liquid-repellent coatings, and a method of characterizing a porous surface for the liquid-repellent coatings. The invention further relates to a porous liquid-repellent coating comprising a porous layer of a transition metal oxide and/or hydroxide and a layer of a liquid-repellent compound deposited onto the porous layer of the transition metal oxide and/or hydroxide, wherein the porous layer of the transition metal oxide and/or hydroxide is comprised of a plurality of surface pores of varying angles with an average angle that is re-entrant.

An object of the present invention is to improve a substrate processing apparatus using the CARE method. The present invention provides a substrate processing apparatus for polishing a processing target region of a substrate by bringing the substrate and a catalyst into contact with each other in the presence of processing liquid. The substrate processing apparatus includes a substrate holding unit configured to hold the substrate, a catalyst holding unit configured to hold the catalyst, and a driving unit configured to move the substrate holding unit and the catalyst holding unit relative to each other with the processing target region of the substrate and the catalyst kept in contact with each other. The catalyst is smaller than the substrate.

Described herein is an improved process for an anticorrosion pretreatment of a metallic surface including steel, galvanized steel, aluminum, magnesium and/or a zinc-magnesium alloy, wherein the metallic surface is brought into contact with an aqueous composition A including a) from 0.01 to 0.5 g/l of a copolymer and the metallic surface is brought into contact with an acidic aqueous composition B including b1) a compound selected from the group consisting of titanium, zirconium and hafnium compounds, wherein the metallic surface is brought into contact i) firstly with the composition A and then with the composition B, ii) firstly with the composition B and then with the composition A and/or iii) simultaneously with the composition A and the composition B. Also described herein is a corresponding aqueous composition A, an aqueous concentrate for producing this composition, a correspondingly coated metallic surface and a method of using a correspondingly coated metallic substrate.