Metal powder particles for use in additive manufacturing are made by removing material from the surface of the particles using wet chemical etching to create a nanoscale texturing of the surface, increasing absorptivity by the metal powder particles of incident laser light and maintaining flowability. The nanoscale texturing has sub-wavelength features at laser wavelengths in the range 800-1100 nm. The particles are substantially spherical and have mean diameters in the range 10-70 μm.

A method for subjecting garment accessories to a surface electrolytic treatment provides various metallic colors to metallic garment accessories in a cost effective manner. The method can provide a first metallic color on one side of outer surface of the garment accessory and provide a second metallic color on the other side of the outer surface, by placing one or more metallic garment accessories in an electrolytic solution in a non-contact state with an anode and a cathode for passing electric current through the electrolytic solution, passing electric current through the electrolytic solution and generating a bipolar phenomenon on the garment accessory.

PROBLEMS TO BE SOLVED: To provide a process for roughening both sides of a copper plate by forming a protrusion with a fine bump shape on the both sides of the copper plate, and then to provide a process for a deterioration of an electroplating solution for plating copper to become hard to progress therein. MEANS FOR SOLVING THE PROBLEMS: First of all, there is designed to be arranged electrodes (3, 3) as a similar pole for therebetween to be opposed to each other in an electroplating copper solution 2, and then to be arranged a copper plate 4 at therebetween. And then at first there becomes to be performed an anodic treatment for generating a copper fine particles on both surfaces of the copper plate 4, by performing an electrolytic process with the copper plate 4 as a positive electrode and the electrodes 3 as negative electrodes. And then thereafter there becomes to be performed a cathodic treatment, by performing an electroplating of copper with the copper plate 4 as a negative electrode and the electrodes 3 as positive electrodes, for the copper fine particles to be fixed onto the surfaces of the copper plate 4. Furthermore, there becomes to be formed the above mentioned protrusion with the fine bump shape thereon, by performing the anodic treatment and then the cathodic treatment as not less than one cycle thereof.

PROBLEMS TO BE SOLVED: To provide a process for roughening both sides of a copper plate by forming a protrusion with a fine bump shape on the both sides of the copper plate, and then to provide a process for a deterioration of an electroplating solution for plating copper to become hard to progress therein. MEANS FOR SOLVING THE PROBLEMS: First of all, there is designed to be arranged electrodes (3, 3) as a similar pole for therebetween to be opposed to each other in an electroplating copper solution 2, and then to be arranged a copper plate 4 at therebetween. And then at first there becomes to be performed an anodic treatment for generating a copper fine particles on both surfaces of the copper plate 4, by performing an electrolytic process with the copper plate 4 as a positive electrode and the electrodes 3 as negative electrodes. And then thereafter there becomes to be performed a cathodic treatment, by performing an electroplating of copper with the copper plate 4 as a negative electrode and the electrodes 3 as positive electrodes, for the copper fine particles to be fixed onto the surfaces of the copper plate 4. Furthermore, there becomes to be formed the above mentioned protrusion with the fine bump shape thereon, by performing the anodic treatment and then the cathodic treatment as not less than one cycle thereof.

A non-uniform initial metal film is non-uniformly deplated to provide a more uniform metal film on a substrate. Electrochemical deplating may be performed by placing the substrate in a deplating bath formulated specifically for deplating, rather than for plating. The deplating bath may have a throwing power of 0.3 or less; or a bath conductivity of 1 mS/cm to 250 mS/cm. Reverse electrical current conducted through the deplating bath non-uniformly. electro-etches or deplates the metal film.

A non-uniform initial metal film is non-uniformly deplated to provide a more uniform metal film on a substrate. Electrochemical deplating may be performed by placing the substrate in a deplating bath formulated specifically for deplating, rather than for plating. The deplating bath may have a throwing power of 0.3 or less; or a bath conductivity of 1 mS/cm to 250 mS/cm. Reverse electrical current conducted through the deplating bath non-uniformly. electro-etches or deplates the metal film.

Provided is a manufacturing method of a surface-treated Zn—Ni alloy electroplated steel sheet, the method comprising the steps of: preparing a Zn—Ni alloy electroplated steel sheet including a steel sheet and a Zn—Ni alloy-plated layer with an Ni content of 5-20 wt % (S1); preparing an alkaline electrolyte solution in which 4-250 g/L of potassium hydroxide (KOH) or sodium hydroxide (NaOH) or both combined are added in distilled water (S2); and inside the alkaline electrolyte solution, placing the Zn—Ni alloy electroplated steel sheet as an anode and installing another metal sheet as a cathode, and applying 2-10 V of an alternating or direct current to conductor electrochemical etching such that a 3-point average value of the arithmetic average roughness (Ra) of the surface of the Zn—Ni alloy electroplated steel sheet reaches 200-400 nm, thereby producing a surface-treated electroplated steel sheet (S3).

A wet etch apparatus includes a wafer chuck, a dispensing nozzle, a liquid etchant container, and an electric field generator. The dispensing nozzle is above the wafer chuck. The liquid etchant container is in fluid communication with the dispensing nozzle. The electric field generator is operative to generate an electric field across the wafer chuck. The electric field generator includes a first electrode and a second electrode spaced apart from the first electrode in a direction substantially perpendicular to a top surface of the wafer chuck, and the second electrode is an electrode plate above the wafer chuck.

A wet etch apparatus includes a wafer chuck, a dispensing nozzle, a liquid etchant container, and an electric field generator. The dispensing nozzle is above the wafer chuck. The liquid etchant container is in fluid communication with the dispensing nozzle. The electric field generator is operative to generate an electric field across the wafer chuck. The electric field generator includes a first electrode and a second electrode spaced apart from the first electrode in a direction substantially perpendicular to a top surface of the wafer chuck, and the second electrode is an electrode plate above the wafer chuck.

Systems and methods for the recovery of noble metal from noble-metal-containing material are generally described. Certain embodiments related to systems and methods in which an electric current is transported between an electrode and the noble metal of a noble-metal-containing material to dissolve at least a portion of the noble metal from the noble-metal-containing material. The dissolved noble metal can subsequently be precipitated out of solution and recovered, according to certain embodiments. Noble metals can be recovered from any suitable noble-metal-containing material, including plated and/or filled scrap materials and/or other materials.