A method for preparing a Cr(III)-plating solution is disclosed. The method comprises or consists of the steps of (a) providing an aged aqueous Cr(III)-solution; (b) adding a polycarbonate or a derivative thereof to the solution of step (a); and (c) adding a borate to the solution of step (b). In addition, a plating solution obtainable by the present method is disclosed, and a plating solution comprising or consisting of Cr(III)-ions, a polycarbonate or a derivative thereof, a borate, water, sulfate, and positive ions selected from the group consisting of hydrogen ions, alkali metal ions and earth alkali metal ions.

A method for preparing a Cr(III)-plating solution is disclosed. The method comprises or consists of the steps of (a) providing an aged aqueous Cr(III)-solution; (b) adding a polycarbonate or a derivative thereof to the solution of step (a); and (c) adding a borate to the solution of step (b). In addition, a plating solution obtainable by the present method is disclosed, and a plating solution comprising or consisting of Cr(III)-ions, a polycarbonate or a derivative thereof, a borate, water, sulfate, and positive ions selected from the group consisting of hydrogen ions, alkali metal ions and earth alkali metal ions.

A method for the electrodeposition of a functional or decorative chromium layer onto a metallic substrate in an electrodeposition process from a halide-ion free and boric acid free aqueous electrolyte solution and to the coated product obtained thereby.

A method for the electrodeposition of a functional or decorative chromium layer onto a metallic substrate in an electrodeposition process from a halide-ion free and boric acid free aqueous electrolyte solution and to the coated product obtained thereby.

A method for producing a black plated resin part includes the steps of electroplating a resin substrate provided with an underlying plating layer in a trivalent chromium plating bath containing thiocyanic acid, to thereby form, on the underlying plating layer, a black chromium plating layer composed of trivalent chromium and having a thickness of 0.15 μm or more; and immersing the resin substrate provided with the black chromium plating layer in warm water at 30° C. or higher for a predetermined time. In the method, the amount of thiocyanic acid contained in the trivalent chromium plating bath, the temperature of the warm water, and the time of immersion of the resin substrate in the warm water are adjusted so that the black chromium plating layer exhibits a b* value of −1.7 or less based on the L*a*b* color system.

A method for producing a black plated resin part includes the steps of electroplating a resin substrate provided with an underlying plating layer in a trivalent chromium plating bath containing thiocyanic acid, to thereby form, on the underlying plating layer, a black chromium plating layer composed of trivalent chromium and having a thickness of 0.15 μm or more; and immersing the resin substrate provided with the black chromium plating layer in warm water at 30° C. or higher for a predetermined time. In the method, the amount of thiocyanic acid contained in the trivalent chromium plating bath, the temperature of the warm water, and the time of immersion of the resin substrate in the warm water are adjusted so that the black chromium plating layer exhibits a b* value of −1.7 or less based on the L*a*b* color system.

A method for metallizing plastic by pre-plating for electroplating, forming a metal bonding layer and a metal transition layer using electro arc ion plating or magnetron sputtering in series, and then forming a metal conductive layer on the metal transition layer using the electro arc ion plating. At least forming the metal conductive layer comprises: disposing a magnetic filter device between a metal target and a vacuum chamber in which the plastic workpiece is placed, so that positively charged metal ions generated by the metal target are deflected by the magnetic filter device and then enter the vacuum chamber to be deposited on the surface of the plastic workpiece.

A method for metallizing plastic by pre-plating for electroplating, forming a metal bonding layer and a metal transition layer using electro arc ion plating or magnetron sputtering in series, and then forming a metal conductive layer on the metal transition layer using the electro arc ion plating. At least forming the metal conductive layer comprises: disposing a magnetic filter device between a metal target and a vacuum chamber in which the plastic workpiece is placed, so that positively charged metal ions generated by the metal target are deflected by the magnetic filter device and then enter the vacuum chamber to be deposited on the surface of the plastic workpiece.

A method of forming a wear-resistant coating on an article includes depositing a chromium coating on a substrate of the article, and subsequently heating the coated article to enhance a plurality of through-cracks within the chromium coating. The method further includes applying a liquid filler material to the coated article such that at least one of the plurality of through-cracks is at least partially occupied by the filler material, and solidifying the liquid filler material.

A method of forming a wear-resistant coating on an article includes depositing a chromium coating on a substrate of the article, and subsequently heating the coated article to enhance a plurality of through-cracks within the chromium coating. The method further includes applying a liquid filler material to the coated article such that at least one of the plurality of through-cracks is at least partially occupied by the filler material, and solidifying the liquid filler material.