Electroplated Coating of Zinc Alloy with Excellent Corrosion Resistance and Plated Metal Material Having Same

Abstract

Objects of the present invention is to provide a zinc-based alloy electroplated film having a high corrosion resistance comparable to Zn—Cr alloy plating without containing chromium which gives a heavy environmental load, and a plated metal material using the same. The present invention relates to a zinc-based alloy electroplated film excellent in corrosion resistance containing (A) 30 to 96% by weight of zinc, (B) 2 to 20% by weight of an iron-group metal, and (C) 2 to 50% by weight of tungsten.

1 . A zinc-based alloy electroplated film containing:
 (A) 30 to 96% by weight of zinc,   (B) 2 to 20% by weight of an iron-group metal, and   (C) 2 to 50% by weight of tungsten.   
   
   
       2 . The zinc-based alloy electroplated film according to  claim 1 , wherein the iron-group metal (B) is iron. 
   
   
       3 . The zinc-based alloy electroplated film according to  claim 1 , which further contains 1 to 30% by weight of a corrosion-inhibiting pigment and/or ceramic particles. 
   
   
       4 . The zinc-based alloy electroplated film according to  claim 3 , wherein the corrosion-inhibiting pigment is at least one selected from the group consisting of phosphate salts, molybdate salts, metaborate salts, and silicate salts. 
   
   
       5 . The zinc-based alloy electroplated film according to  claim 3 , wherein the ceramic particles are particles of at least one member selected from the group consisting of Al 2 O 3 , SiO 2 , TiO 2 , ZrO 2 , Y 2 O 2 , ThO 2 , CeO 2 , Fe 2 O 3 , B 4 C, SiC, WC, ZrC, TiC, graphite, graphite fluoride, BN, Si 3 N 4 , TiN, Cr 3 B 2 , ZrB 2 , 2MgO.SiO 2 , MgO.SiO 2 , and ZrO 2 .SiO 2 . 
   
   
       6 . The zinc-based alloy electroplated film according to  claim 1 , which further contains at least one organic compound selected from the group consisting of alkynes, alkynols, amines or salts thereof, thio compounds, aromatic carboxylic acid compounds or salts thereof, and heterocyclic compounds in the plated film in an amount of 0.001 to 10% by weight in terms of C (carbon) content. 
   
   
       7 . A plated metal material, which has the zinc-based alloy electroplated film according to  claim 1 . 
   
   
       8 . A plated metal material, wherein the zinc-based alloy electroplated film according to  claim 1  is formed on a metal material and then is brought into contact with an acidic aqueous solution containing at least one element selected from the group consisting of cobalt, nickel, titanium, and zirconium.