The invention relates to an aqueous, alkaline electrolyte for electrochemically depositing a zinc-, iron-, manganese-containing layer onto surfaces of metal piece goods, in particular piece goods made of iron and/or steel, characterized in that the electrolyte contains: zinc ions in an amount of 4-60 g/L; iron ions in an amount of 0.5-30 g/L; manganese ions in an amount of 0.1-15 g/L. The invention also relates to a method for electrochemically depositing a zinc-, iron-, manganese-containing layer onto one or more surfaces of a metal piece good. The invention also relates to a metal piece good comprising a zinc-, iron, manganese-containing layer electrochemically deposited onto a surface of the metal piece good in accordance with the inventive method.

The purpose of the present invention is to provide a zinc-nickel-silica composite plating bath that has been improved in terms of: covering power for articles having a complex shape; and corrosion resistance of a low current density portion where the film thickness is small. The present invention pertains to a zinc-nickel-silica composite plating bath, the plating bath having a pH of 3.5 to 6.9, and containing zinc ions, nickel ions, colloidal silica, and chloride ions. The colloidal silica is a cationic colloidal silica having on the surface thereon at least one species of metal cation selected from the group consisting of trivalent to heptavalent metal cations.

The present disclosure provides electrolyte solutions for electrodeposition of zinc-manganese alloys, methods of forming electrolyte solutions, methods of electrodepositing zinc-manganese alloys, and multilayered zinc-manganese alloys. An electrolyte solution for electroplating can include a metal salt, boric acid, an alkali metal chloride, polyethylene glycol, and a hydroxy benzaldehyde. An electrolyte solution can be formed by dissolving a metal salt, boric acid, an alkali metal chloride, polyethylene glycol, and a hydroxy benzaldehyde in water or an aqueous solution. Electrodepositing zinc-manganese alloys on a substrate can include introducing a cathode and an anode into an electrolyte solution comprising a metal salt, boric acid, an alkali metal chloride, polyethylene glycol, and a hydroxy benzaldehyde. Electrodepositing can further include passing a current between the cathode and the anode through the electrolyte solution to deposit zinc and manganese onto the cathode.

The alkaline zinc-iron plating bath according to the present invention includes a zinc compound, an alkali hydroxide, a metal salt containing iron, and a complexing agent, in which the complexing agent is an aliphatic compound having five or more hydroxy groups. When the aliphatic compound having a chain structure and five or more hydroxy groups is used as the complexing agent, for example, due to an inhibitor effect thereof, redissolution of a deposited plating film is prevented; and as a result, a thick plating film can be efficiently formed.

In example implementations, a method for producing a coating is provided. The method includes placing a magnesium substrate into an anodizing bath, applying a voltage for a first amount of time to form a micro-porous anodizing layer having a thickness of between 1 to 50 microns on the magnesium substrate, placing the magnesium substrate with the micro-porous anodizing layer in plating bath, wherein the plating bath comprises a metal and a complexing agent with a pH between 8 and 14, applying a first current to the plating bath for a second amount of time to form an interlock layer on the micro-porous anodizing layer, and applying a second current to the plating bath for a third amount of time to form a coating on the interlock layer.

The present invention concerns a metal or metal alloy deposition composition, particularly a copper or copper alloy deposition composition, for electrolytic deposition of a metal or metal alloy layer, particularly for electrolytic deposition of a copper or copper alloy layer, comprising at least one type of metal ions to be deposited, preferably copper ions, and at least one imidazole based plating compound. The present invention further concerns a method for preparation of the plating compound, the plating compound itself and its use in a metal or metal alloy deposition composition. The inventive metal or metal alloy deposition composition can be preferably used for filling recessed structures, in particular those having higher diameter to depth aspect ratios.

A conductive electrode wire for use in an electric discharge machine (EDM) is provided, comprising a core wire comprised of one single metal or an alloy of multiple metals with a coating deposited by the electro-plasma process, wherein such coatings are alloys of zinc and nickel. A process for treating a surface of an electrically conductive workpiece, such as a core wire, is also provided.

A threaded connection for pipes according to the present embodiment includes a pin, a box, and a Zn—Ni alloy plating layer. The pin has a pin contact surface that includes an external thread part. The box has a box contact surface that includes an internal thread part. The Zn—Ni alloy plating layer is disposed on or above at least one of the pin contact surface and the box contact surface. The Zn—Ni alloy plating layer contains graphite.

A threaded connection for pipe includes a pin and a box. The threaded connection for pipe includes a Zn—Ni alloy plated layer and a solid lubricant coating. The Zn—Ni alloy plated layer is formed on a contact surface of at least one of the pin and the box and contains 10 to 16 mass % of Ni. The solid lubricant coating is formed on the Zn—Ni alloy plated layer. The contact surface on which the Zn—Ni alloy plated layer is formed is ground. Now define arithmetic average roughness of the surface of the Zn—Ni alloy plated layer as Ra1, and arithmetic average roughness of the contact surface as Ra2. Ra1 ranges from 0.1 to 3.2 μm. Ra1 is more than Ra2.

A method for depositing a zinc-nickel alloy on a substrate, including: (a) providing the substrate, (b) providing an aqueous zinc-nickel deposition bath as catholyte in a compartment, wherein the compartment includes an anode and anolyte, the anolyte being separated from catholyte by a membrane, and the catholyte includes nickel ions, complexing agent, zinc ions, (c) depositing zinc-nickel alloy onto the substrate, wherein after step (c) nickel ions have lower concentration than before step (c), (d) rinsing the zinc-nickel coated substrate in water, obtaining a rinsed zinc-nickel coated substrate and rinse water including a portion of the complexing agent and nickel ions, wherein (i) a portion of rinse water and/or a portion of catholyte is treated in a first treatment compartment to separate water from the complexing agent and the nickel ions, (ii) returning the separated complexing agent to the catholyte, and (iii) adding nickel ion to the catholyte.