A silver-plated product which has more excellent minute sliding abrasion resistance property than that of conventional silver-plated products, and a method for producing the same. The silver-plated product is produced by electroplating a base material 10 of copper or a copper alloy to form an underlying plating layer 12 of nickel or a nickel alloy, a first silver-plating layer of silver (lower silver-plating layer) 14, a zinc-plating layer 16 of zinc serving as an intermediate plating layer, and a second silver-plating layer of silver (upper silver-plating layer) 18 serving as a surface layer, in this order from the base material 10.

The invention discloses a high-precision zinc-based alloy electrode wire, the external shell thereof consisting of: Zn: 70.5-95%; Cu: 2.5-27%; X: 0.02-4.0%; Y: 0.002-0.4%, and unavoidable impurities; where, X refers to any two kinds of metals selected from Ni, Ag, Cr, Si and Zr, and the weight percentage of each of these two kinds of metals is 0.01-2.0%; and Y refers to any two kinds of metals selected from Ti, Al, Co, B, and P, and the weight percentage of each of these two kinds of metals is 0.001-0.2%; the -phase in a metallurgical structure of the external shell is above 80 wt %. The invention also provides a method for manufacturing the electrode wire, which has high surface smoothness of the cut metal workpieces to improve the cutting precision. The method has simple process, high maneuverability, less steps, so as to facilitate large-scale and automated production.

Provided is a method for surface-treatment of a metal using bacteria, and more particularly, a method for surface-treatment of a metal using bacteria including immersing the metal having a surface layer on which a deformed layer is formed in a culture fluid cultured with metal-oxidizing bacteria, such that the metal-oxidizing bacteria selectively oxidize and leach-remove the deformed layer of the metal to perform micro-machining, thereby minimizing a damage to a metal basic material to effectively remove the deformed layer of the metal, and further including partly coating a surface of the metal to produce fine patterns of which sizes and shapes are various.

A surface treatment agent including a compound (P) represented by R.sup.1P(O)(OR.sup.2)(OR.sup.3) in which R.sup.1 is an alkyl group, an alkoxy group, a fluorinated alkyl group, or an aromatic hydrocarbon group which may have a substituent, and R.sup.2 and R.sup.3 are each independently a hydrogen atom, an alkyl group, a fluorinated alkyl group, or an aromatic hydrocarbon group which may have a substituent; a compound (S) represented by RSH . . . in which R is an alkyl group having 3 or more carbon atoms, a fluorinated alkyl group having 3 or more carbon atoms, or an aromatic hydrocarbon group which may have a substituent; and a solvent.

Provided is a method for manufacturing a brass-plated steel wire in which improvement in the quality of the brass-plated steel wire and energy saving in the manufacturing process are balanced and a brass-plated steel wire obtained by the method. The method is a method for manufacturing a brass-plated steel wire comprising a plating process in which a steel wire rod is brass plated and a final wire drawing process in which the obtained brass-plated steel wire rod is subjected to a final drawing. The method includes a zinc oxide removing process in which the amount of zinc oxide on the surface of the brass-plated steel wire rod is made smaller than 50 mg/m.sup.2 before the final wire drawing process.

A method for smoothing surfaces of a copper foil and the copper foil obtained are provided, wherein the method for smoothing surfaces of the copper foil includes the following steps. Supplied with a copper foil. A first electropolishing process is performed on the copper foil. The copper foil is subjected to a pickling process. A second electropolishing process is performed on the copper foil.

The invention provides improved techniques for bonding devices using copper-to-copper or other types of bonds. A substrate is cleaned to remove surface oxides and contaminants and then rinsed. The rinsed substrate is provided to coating unit where a protective coating is applied to the substrate. The protective coating may be applied by immersing the substrate in a bath or via chemical vapor deposition. In an aspect, the protective coating may be copper selective so that the protective coating is only applied to copper features of the substrate. The protective coating minimizes formation of oxides and other bond weakening forces that may form during bonding processes, such as bonding a copper wire to a copper bond pad of the substrate. In an aspect, an annealing process is used to cure the protective coating and remove small imperfections and other abnormalities in the protective coating prior to the bonding process.