| 摘要 |
A metallic coating is provided on at least one electrically conductive substrate by tumbling in a tumbling barrel the substrate or substrates and a liquid (e.g. water) containing (i) ions of a dissolved salt of a plating metal; and (ii) particles of a driving metal or driving metal alloy, which driving metal is or which metals in the driving metal alloy are less noble than the plating metal: the pH of the liquid being such as will dissolve the driving metal or driving metal alloy during plating. It is to be understood that the "driving" metal or metal alloy induces plating. The tumbling barrel may be simultaneously rotated and axially reciprocated. The examples illustrate various components which can be used in the tumbling barrel. The plating metal (a), driving metal powder (b), and the object to be plated (c) are as follows:- .a.b.c. .I.Sn.Al.steel .II.Sn.Mn.steel .III.Sn.Mg.steel .IV.Sn.Ti.steel .V.Sn.Zn.steel .VI.Cd.Al.steel .VII.Pb.Zn.steel .a.b.c. .VIII.Hg.Zn.steel .IX.Ag.Zn.steel .X.Tl.Zn.steel .XI.Sn.Zn.Cu .XII.Sn.Zn.Mo .XIII.Sn.Zn.brass .XIV.Ni.Al.steel The following are also given:- .a.b.c .Zn.Mg.Fe .Sn.Al.Zn plated part Specified driving metals in alloy form are Al:Mn; Al:Zn and Sn:Al:Zn. Glass beads may be used as impact media in the tumbling barrel. Massive articles, small parts such as washers or flakes or granules may be plated. Ferrous metal parts plated with Sn by the method may afterwards be plated mechanically or electrically with Zn or Cd. A solid product to add to H2O to effect plating may comprise 1) a mixture of a plating metal salt, driving metal powder and means for preventing intimate contact of the salt and powder in the absence of water (e.g. 1 or 2 drops of diethanolamine or n-tallow or 1,3-propylene diamine) all pressed into a pellet or 2) the plating metal salt and gum-encased driving metal particles pressed into a single cake or incorporated in a textile or abrasive product. |
