Additive for copper deposition in mechanical zinc-copper plating process

Abstract

The invention discloses an additive for copper deposition in a mechanical zinc-copper plating process, and belongs to the technical field of surface treatment for metal fittings. The additive is prepared from, by mass, 2%-3% of copper sulfate, 0.6%-1% of ascorbic acid, 1%-2% of sodium bentonite, 15%-18% of stannous mono-sulphate, 1%-2% of OP-10, 3%-5% of sulfuric acid, 2%-4% of polyethylene glycol 600 and the balance water. The additive for copper deposition in the mechanical zinc-copper plating process is used in a mechanical plating method for forming a zinc-copper composite plating layer on the surface of a steel product. In the using process, a traditional mechanical zinc plating method is adopted at first for plating the surface of the steel product with a zinc layer with the preset thickness, then, the additive is adopted in an assisted mode for plating the surface of the zinc plating layer with a copper layer, and finally the zinc-copper composite plating layer with excellent corrosion resistance and the beautiful appearance can be obtained on the surface of the steel product.

Description

technical field [0001] The invention relates to an additive for depositing copper in a mechanical galvanizing-copper process, which belongs to the technical field of surface plating of iron and steel parts and is used for zinc-copper composite plating treatment on the surface of hardware and steel parts. Background technique [0002] With the continuous improvement of the quality requirements of the manufacturing industry for the surface plating layer, a single mechanical galvanized layer is difficult to meet the needs of the hardware industry; this provides a good opportunity for the development of the composite mechanical plating process. The zinc coating can provide excellent corrosion resistance for the steel substrate, the copper and copper alloy coating can provide colorful and beautiful decorative effects for the steel substrate, and the zinc-copper composite coating can provide the steel substrate with corrosion resistance + decoration double function. Electroplatin...

AI Technical Summary

Problems solved by technology

[0004] The invention patent (application number 2015105706970) proposes a deposition accelerator for mechanical copper plating and copper alloy coating, the invention patent (application number 2015105710181) proposes a mechanical copper plating and copper alloy process, and the invention patent (application number 2015105710410) proposes A kind of accelerator for mechanical copper plating and copper alloy and its application method are disclosed. They belong to the direct copper plating on the surface of steel substrate, or the zinc-tin transition layer on the surface of substrate (also known as the bottom layer, the thickness is relatively thin, about 1~ 3 microns) copper-plated on the surface, but not copper-plated on the surface of a certain thickness of mechanical galvanized layer

What they have in common is that the accelerator contains triethanolamine and ammonium salt, and there is no reaction between triethanolamine and the substrate steel, and it has a corrosive effect on the surface of copper, aluminum, zinc and their alloys, which can ensure the bonding of the copper plating layer on the surface of the steel substrate. It can also ensure the bonding strength between the copper powder particles in the coating; but when copper is plated on the surface of the zinc layer with a certain thickness, because triethanolamine acts on the surface of zinc and copper at the same time, it is difficult to form a firm bond on the surface of the zinc layer. Copper layer, in addition, triethanolamine has certain toxicity and is not environmentally friendly

[0005] Engineers in the field of mechanical galvanizing technology adopt the conventional mechanical galvanizing process. Firstly, a zinc layer of required thickness is prepared on the surface of the substrate, and then the zinc powder is replaced with copper powder or copper alloy powder. Or the method of adding copper sulfate or other copper salts to the zinc layer to coat the copper layer on the surface of the zinc layer, but the attempts all ended in failure.