Method for plating decorative chromium by die-cast zinc alloy part

Abstract

The invention discloses a method for plating decorative chromium by a die-cast zinc alloy part. The method comprises the steps of: (1) treatment before plating ; (2) cyanide-free copper preplating; (3) acid copper plating; (4) electroplating of semi-bright nickel; (5) electroplating of high-sulfur nickel; (6) electroplating of bright nickel; and (7) electroplating of chromium. An obtained plating layer is uniform in plating film thickness, high in corrosion resistance, high in hardness, bright and smooth in surface, free of generation of scales, peeling, fading and color changing and suitable for decorative chromium plating treatment of decorative parts, artware and the like.

Description

technical field

[0001] The invention relates to the field of electroplating, in particular to a method for decorative chrome plating of die-cast zinc alloy parts. Background technique

[0002] Due to its cheap price, low melting point, and especially good die-casting process performance, zinc alloy has been widely used in the manufacture of small hardware accessories, and can also be used to manufacture decorative and practical metal parts. Such as various zippers, belt buckles, luggage accessories, car nameplates and military badges, etc.

[0003] The appearance of zinc alloy die castings is gray and white, and there are various defects on the surface, such as: slag inclusions, shrinkage cavities, etc. Therefore, without surface treatment, its usability and decoration are very poor. A common surface treatment method is electroplating. According to the different decorative and functional requirements, there are certain differences in the electroplating process. For exampl...