A kind of electroplating tin additive and preparation method thereof

Abstract

The invention belongs to the technical field of electroplating, and in particular relates to an electroplating tin additive and a preparation method thereof, at least comprising the following components: quaternized polyhydroxy Gemini surfactant; benzoic acid. The additive provided by the invention cooperates with benzoic acid with quaternized polyhydroxy Gemini surfactant to form a tight covering film layer on the surface of the cathode, thereby effectively inhibiting the reduction and deposition of impurity metal ions on the surface of the cathode, and significantly reducing the tin coating. The content of inorganic impurities makes the coating more uniform and fine, the thickness is more uniform, and the weldability is improved.

Description

technical field [0001] The invention belongs to the technical field of electroplating technology. More specifically, it relates to an electroplating tin additive and a preparation method thereof. Background technique [0002] Aluminum alloy is the most widely used non-ferrous metal structural material in industry, and has been widely used in aviation, aerospace, automobile, machinery manufacturing, shipbuilding and chemical industry. With the rapid development of industrial economy, the demand for welded structural parts of aluminum alloy is increasing day by day, so that the research on weldability of aluminum alloy is also in-depth. Tin plating on aluminum and aluminum alloys can improve the weldability of aluminum and aluminum alloys, but tinning cannot be done directly on the aluminum surface, and a series of pretreatments are required, such as electroless nickel plating, hard chrome plating and other metal coatings, etc. These pretreatments can significantly improve t...

AI Technical Summary

Problems solved by technology

Tin plating on aluminum and aluminum alloys can improve the weldability of aluminum and aluminum alloys, but tinning cannot be done directly on the aluminum surface, and a series of pretreatments are required, such as electroless nickel plating, hard chrome plating and other metal coatings, etc. These pretreatments can significantly improve the surface hardness, wear resistance and corrosion resistance of aluminum and aluminum alloys, and expand their application range. However, these pretreatment methods lead to many impurities such as nickel ions and chromium ions in the electroplating process. Dissolution and deposition on the cathode surface

The deposition of these impurities on the surface of the cathode causes the inclusion of the coating. The coating may change the surface oxidation state due to the inclusion, making the surface more easily oxidized, or changing the size and orientation of the crystal grains of the deposited layer, which ultimately affects the quality of the coating.

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