A method of manufacturing a bright surface product comprises a step of performing electroless plating to form a first metal film on a base coat layer formed on a substrate, a step of performing electrolytic plating to form a second metal film thereon so that the bonding strength between each film of a multi-layered metal film comprising the first metal film and the second film is higher than the bonding strength between the base coat layer and the first metal layer, a step of integrally and discontinuously segmentalizing the multi-layered metal film with cracks to form an island-like metal film comprising a collection of fine multi-layered metal regions with island-like structures; and a step of forming a translucent top coat layer to cover the fine multi-layered metal regions of the island-like metal film and enter into the cracks to make contact with the base coat layer.

A piston ring includes a base body having an inner circumferential surface, first and second flank surfaces and an outer circumferential surface, wherein a first hard chromium layer with a crack network is applied to the outer circumferential surface and has a crack density of 10-250 cracks per mm and solid particles having an average particle size of 0.01-10 μm embedded in cracks of the first hard chromium layer, a second hard chromium layer having a crack network applied to the first hard chromium layer and having a crack density of the crack network of 10-250 cracks per mm, no solid particles being embedded in the cracks thereof, where the cracks have an average width of 1-15 μm, the cracks are electrolytically expanded and the surface proportion of the cracks are 3-25% based on a total surface of the second hard chromium layer.

A method of forming a multilayered zinc alloy coating comprises steps of providing a bath of an aqueous electrolyte including zinc and a second electrodepositable component in an electrolytic cell having an anode and a cathode; applying a current or voltage between the anode and the cathode; modulating the applied current or voltage over time between at least two current or voltage values to thereby modulate the current density over multiple cycles between at least two current density values, wherein a first current density value is in a range of 0.3 to less than 2 A/dm.sup.2 and a second current density value is higher than the first current density value and is in a range of 0.6 to less than 5 A/dm.sup.2; and controlling the modulation of the applied current or voltage to obtain a multilayered structure having multiple layers of one or more of alternating proportions of the second component, alternating corrosion potential, alternating grain size, and alternating grain orientation, wherein one or more of the multiple layers has a thickness in the range of 1 to 10 μm.

The present invention relates to a galvanic process additivated with nanotechnology, wherein silver nanoparticles are added to the composition of a galvanic bath (10b), capable of forming a nickel layer (101), onto which a chrome layer (102) is deposited to form a material with antibacterial properties, which may be applied in manufacturing the most varied devices or materials.

A bioactive coated substrate includes a base substrate, a bioactive metal-containing layer disposed over the base substrate, and an electroplated chromium layer disposed on the bioactive metal-containing layer. The electroplated chromium layer defines a plurality of cracks or pores that expose the bioactive metal-containing layer.

A method includes: agitating base members that has been immersed in an electrolytic solution inside of an electroplating tank so as to flow in a circumference direction along an inner wall of the electroplating tank; and electroplating the base members flowing along the circumference direction in the electrolytic solution inside of the electroplating tank. The flow of the base members along the circumference direction is caused by a flow of magnetic media along the circumference direction in the electrolytic solution inside of the electroplating tank or is caused by rotation of an agitation unit provided at a bottom side of the electroplating tank. At least one of the base members touches a bottom cathode, and a base member positioned upward relative to the base member touching the bottom cathode is electrically connected to the bottom cathode via at least the base member touching the bottom cathode.

The present invention is to provide a chrome-plated part having a corrosion resistance in normal and specific circumstances and not requiring additional treatments after chrome plating, and to provide a manufacturing method of such a chrome-plated part. The chrome-plated part 1 includes: a substrate 2; a bright nickel plating layer 5b formed over the substrate 2; a noble potential nickel plating layer 5a formed on the bright nickel plating layer 5b. An electric potential difference between the bright nickel plating layer 5b and the noble potential nickel plating layer 5a is within a range from 40 mV to 150 mV. The chrome-plated part 1 further includes: a trivalent chrome plating layer 6 formed on the noble potential nickel plating layer 5a and having at least any one of a microporous structure and a microcrack structure.

The invention relates to a method for producing an anti-corrosion coating for hardenable sheet steels, wherein at least two metal layers are deposited one after another onto the steel substrate; the one metal layer is a zinc layer or zinc-based layer and the other layer is a layer composed of a metal that forms baser intermetallic phases with Zn or Fe and has a higher oxidation potential than Zn, namely Ni, Cu, Co, Mn, or Mo, or a layer based on these metals; and an anti-corrosion coating for hardenable sheet steels.

There is provided an inexpensive plated product, which can prevent the increase of the contact resistance of a silver-plating film and the change of the color of the surface thereof after reflow-treating a plated product wherein the silver-plating film is formed on a portion of the surface thereof and wherein a tin-plating film is formed on a portion of the other portion of the surface thereof, and a method for producing the same. The plated product is produced by a method including the steps of: forming a nickel-plating film 12 on a surface of a base material 10 of copper or a copper alloy; forming a silver-plating film 16 on a portion of a surface of the nickel-plating film 12, and forming a tin-plating film 20 on a portion of the other portion of the surface of the nickel-plating film 12, to prepare a plated product which has the silver-plating film 16 and the tin-plating film 20 on the surface of the nickel-plating film 12 formed on the base material 10; and irradiating the surface of the plated product with infrared rays to heat the surface thereof to reflow-treat the tin-plating film 20 to cause the tin-plating film 20 to be a reflowed tin-plating layer 22.

An object including a chromium-based coating on a substrate and a method for its production are disclosed. The chromium-based coating having a first layer on the substrate, wherein the first layer has a top surface on the opposite side to the substrate and includes fissures within the first layer, and wherein the material of the first layer is predominantly formed of chromium and chromium carbide; the chromium-based coating further having a second layer on the first layer, the second layer at least partially filling the fissures in the first layer and at least partially covers the top surface of the first layer, wherein the material of the second layer is selected from a group consisting of: chromium oxide, carbon, and a combination of chromium oxide and carbon.