An electroless plating process that enables reduction in production costs and a two-layer plating film obtained by the process including an electroless plating process for forming a nickel plating film and a gold plating film in this order on a surface of a copper material by a electroless plating method. The electroless plating process includes a step of forming a nickel plating film containing boron by a reductive electroless nickel strike plating method, and a step of forming a gold plating film by a reductive electroless gold plating method. The two-layer plating film according to the present disclosure is formed by this process.

An electroless plating process that enables reduction in production costs and a two-layer plating film obtained by the process including an electroless plating process for forming a nickel plating film and a gold plating film in this order on a surface of a copper material by a electroless plating method. The electroless plating process includes a step of forming a nickel plating film containing boron by a reductive electroless nickel strike plating method, and a step of forming a gold plating film by a reductive electroless gold plating method. The two-layer plating film according to the present disclosure is formed by this process.

An electroless nickel or cobalt plating solution, comprising nickel ions or cobalt ions, Ti.sup.3+ ions as reducing agent for reducing said nickel ions and cobalt ions, at least one accelerator selected from the group consisting of sulfites, dithionites, thiosulfates, tetrathionates, polythionates, disulfites, sulfides, disulfide, polysulfide, elemental sulfur and mixtures thereof; and one or more than one complexing agent,
wherein the pH value of the plating solution is from 5 to 10.5.

An electroless nickel or cobalt plating solution, comprising nickel ions or cobalt ions, Ti.sup.3+ ions as reducing agent for reducing said nickel ions and cobalt ions, at least one accelerator selected from the group consisting of sulfites, dithionites, thiosulfates, tetrathionates, polythionates, disulfites, sulfides, disulfide, polysulfide, elemental sulfur and mixtures thereof; and one or more than one complexing agent,
wherein the pH value of the plating solution is from 5 to 10.5.

An object is to coat a target position on a substrate with a dense film. In order to achieve the object, while a substrate on which a base containing a coating material is formed is transported, an auxiliary agent is applied to the substrate, and then a main agent containing a coating material is applied to the substrate to react the main agent with the auxiliary agent, so that a portion on the substrate where the base is formed is coated with the coating material.

An assembly for electroless metallization of a target surface (11) of at least one workpiece (10), comprising—a container (13) for receiving an electrolyte solution—an inlet for the electrolyte solution, said inlet arranged in the base (15) of the container (13), wherein the inlet (20) is designed as an inlet port (21) with a diffuser plate (24) comprising inlet openings (25) arranged in concentric circles—an outlet (30) which is arranged on an upper side of the container (13)—a receiving area for holding the at least one workpiece (10), wherein the diffuser plate (24) is formed as a first assembly (31) and a second assembly (32), which is identical to the first assembly, of a respective plurality of inlet openings (25), wherein the assemblies at least partially but not completely overlap, and the inlet (20) has at least two inlet ports (21, 22).

An assembly for electroless metallization of a target surface (11) of at least one workpiece (10), comprising—a container (13) for receiving an electrolyte solution—an inlet for the electrolyte solution, said inlet arranged in the base (15) of the container (13), wherein the inlet (20) is designed as an inlet port (21) with a diffuser plate (24) comprising inlet openings (25) arranged in concentric circles—an outlet (30) which is arranged on an upper side of the container (13)—a receiving area for holding the at least one workpiece (10), wherein the diffuser plate (24) is formed as a first assembly (31) and a second assembly (32), which is identical to the first assembly, of a respective plurality of inlet openings (25), wherein the assemblies at least partially but not completely overlap, and the inlet (20) has at least two inlet ports (21, 22).

A method for forming a nickel plated graphene hollow sphere is based on self assembly of graphene under the actions of a rotation force and the van der Waals force, and an electroless nickel plating process performed on the exposed surface of the graphene by means of a hydrothermal method. The method is simple to implement at low cost, and the nickel plated graphene hollow sphere product can be produced with good reproducibility and a high yield. The nickel plated graphene hollow sphere formed by the present method can exhibit good electromagnetic wave absorbing performances of both nickel and graphene, and may have a lower overall density.

A method for forming a nickel plated graphene hollow sphere is based on self assembly of graphene under the actions of a rotation force and the van der Waals force, and an electroless nickel plating process performed on the exposed surface of the graphene by means of a hydrothermal method. The method is simple to implement at low cost, and the nickel plated graphene hollow sphere product can be produced with good reproducibility and a high yield. The nickel plated graphene hollow sphere formed by the present method can exhibit good electromagnetic wave absorbing performances of both nickel and graphene, and may have a lower overall density.

The invention relates to metallic substrates surface coated with a coating layer comprising a metal and an additive.