| 摘要 |
<p>Improved corrosion resistance of base metal hardened gold plating is achieved by the electrodeposition of a ductile, low-stress nickel coating on the substrate prior to the electrodeposition of the metal-hardened gold plating. The nickel coating is electrodeposited from a bath containing a Ni salt, an electrolyte eg boric and/or formic acid, o-formyl benzene sulphonic acid, and optionally a blend of K perfluoroalkyl sulphonates as wetting agent. The gold coating is electrodeposited from a bath containing a Au salt, an electrolyte eg acetic, citric and/or formic acid, and a Au hardener metal salt, eg of Co, In, Ni and/or Zn. Both electrodeposition steps may use insoluble anodes.</p> |
