A method for preparing a zinc-copper composite coating on the surface of a copper-aluminum composite row

Abstract

The invention provides a method for preparing a zinc-copper composite plating layer on the surface of a copper-aluminum composite row. The method includes the following steps that firstly, hot dippingoil removing is conducted; secondly, NaOH alkali liquid is prepared and alkali cleaning is conducted; thirdly, mixed acid liquid is prepared and acid pickling is conducted; fourthly, surface zinc deposition is conducted; fifthly, surface copper preplating is conducted; sixthly, tin plating is conducted; and seventhly, drying treatment is conducted. The composite plating layer is high in chemicalstability, resistant to oxidation in air and is not likely to be subjected to color changing; copper in electroplating copper has good electric conductivity and mechanical performance, copper is likely to be activated, good intermetallic bonding can be formed between copper and other metal plating layers, and therefore good bonding force can be obtained between the plating layers. The plating layer is good in electric conducting performance, the bottoming layer of the plating layer is a zinc-copper composite layer, the surface electric conductivity reaches 90% or higher, and the electric conductivity of the surface zinc plating layer reaches 85% or higher.

Description

technical field [0001] The invention belongs to the technical field of copper-aluminum composite materials, and in particular relates to a method for preparing a zinc-copper composite coating on the surface of a copper-aluminum composite row. Background technique [0002] In recent years, copper-aluminum composite conductor materials have been widely used to replace pure copper bars. Copper-aluminum composite bars have absolute advantages in large-scale production and product prices. Extensive promotion is also one of the research and development directions of new material technology that is supported by the national medium and long-term development plan. However, since the surface and ends of the copper-aluminum composite material have part of the aluminum exposed in the air, the contact surface of the two metals is very easy to form an electrolyte under the action of moisture, carbon dioxide and other impurities in the air, thus forming a battery with aluminum as the negat...

AI Technical Summary

Problems solved by technology

However, since the surface and ends of the copper-aluminum composite material have part of the aluminum exposed in the air, the contact surface of the two metals is very easy to form an electrolyte under the action of moisture, carbon dioxide and other impurities in the air, thus forming a battery with aluminum as the negative electrode. 1. The primary battery with copper as the positive electrode causes electrochemical corrosion of aluminum, resulting in an increase in the contact resistance at the joint between copper and aluminum

The increase of contact resistance will cause the temperature to rise during operation, and the corrosion and oxidation will intensify at high temperature, resulting in a vicious circle, further deteriorating the connection quality, and finally causing the contact point temperature to be too high and even accidents such as smoking and burning.

Therefore, it is very critical to protect the surface of copper-aluminum composite row. In the prior art, an appropriate electroplating process is usually used to treat pure copper row. However, the electroplating of copper-aluminum composite row is fundamentally different from that of pure copper row. and electroplating process, so the electroplating process of pure copper is not suitable for copper-aluminum composite row