CN108048889B

CN108048889B - Surface treatment process of copper-aluminum bimetallic material

Info

Publication number: CN108048889B
Application number: CN201711292350.XA
Authority: CN
Inventors: 董晓文; 王连忠; 沙均洋
Original assignee: YANTAI FISEND BIMETAL CO Ltd
Current assignee: YANTAI FISEND BIMETAL CO Ltd
Priority date: 2017-12-08
Filing date: 2017-12-08
Publication date: 2020-03-20
Anticipated expiration: 2037-12-08
Also published as: CN108048889A

Abstract

The invention provides a copper-aluminum bimetal materialThe surface treatment process comprises the following steps: (1) hot dipping to remove oil; (2) washing with water; (3) alkali washing; (4) washing with water; (5) anodizing; (6) high-temperature water sealing; (7) washing with water; (8) tin plating: 30-50 g/L of stannous sulfate, 120-150 g/L, X g/120 g/L, DS g/15-25 g/L of brightening agent and current controlled at 0.8-1.2A/dm²Controlling the temperature to be 15-25 ℃; (9) washing with water; (10) and (5) drying. The method comprises the steps of anodizing the copper-aluminum composite bar to form a layer of compact insulating aluminum oxide on the surface of aluminum, protecting aluminum element, preventing the aluminum element from participating in a subsequent electroplating process, and activating the surface of copper at an anode; the copper-aluminum composite bar is directly electroplated with tin, so that the intermediate procedures of zinc dipping and pre-copper plating are reduced, and the electroplating protection effect is achieved.

Description

Surface treatment process of copper-aluminum bimetallic material

Technical Field

The invention belongs to the technical field of copper-aluminum composite materials, and particularly relates to a surface treatment process of a copper-aluminum bimetallic material.

Background

As a novel conductor material, the copper-aluminum composite bar has the advantages of good electrical and thermal conductivity of copper materials, light weight, economy and the like of aluminum materials. With the continuous development of science and technology, the copper-aluminum composite process in China has reached the international advanced level, the national standard is issued and implemented successively, the ASTM standard is established by leading participation of China, the product is gradually accepted by customers at home and abroad, and the product is widely applied to a plurality of industries. However, the electrode potential difference exists between copper and aluminum, the surface is not protected, and the copper-aluminum alloy is used in normal atmospheric environment without problems; if under the corrosive medium, the copper-aluminum interface can produce galvanic reaction, and the copper-aluminum interface can be corroded, thereby affecting the use of the product. Therefore, in order to ensure stability during use, the surface of the product is usually required to be subjected to tin electroplating protection treatment so as to achieve the effects of corrosion prevention and increase of the contact area between rows.

As a single metal, the aluminum element belongs to a dual metal, can react with acid and alkali, and has no proper electroplating solution for direct electroplating; the coating has strong affinity to oxygen, and an oxide film is easily formed on the surface; the electrode potential of the aluminum is very negative, and the aluminum is easy to be replaced with metal ions with a positive potential when being immersed into electroplating solution, so that the binding force of a plating layer is influenced; it is usually necessary to coat the aluminum substrate with an underlayer or interlayer before electroplating. The surface protection measure for the aluminum substrate is mature at present, namely an anodic oxidation process, namely a compact oxide layer is formed on the surface of the aluminum substrate, and the aluminum substrate has good corrosion resistance, electrical insulation and high thermal insulation. The copper element electroplating process is relatively simplified, other metals can be directly electroplated after the surface is activated, and compact alloy is easily formed between the copper element and the tin element.

Because the copper-aluminum composite bar is bimetal, the characteristics of the two metals need to be fully considered in the electroplating process so as to achieve the protection effect and avoid secondary corrosion caused in the electroplating process. The existing electroplating scheme is based on an aluminum electroplating process, and the method comprises the steps of removing oil on the surface, performing zinc dipping twice, pre-plating a layer of copper (alloy formed among copper and tin is utilized to ensure the binding force after electroplating), and finally plating tin, wherein the production process is long although the process is mature.

Disclosure of Invention

The invention provides a surface treatment process of a copper-aluminum bimetallic material, which solves the defect of long production process of a treatment method in the background technology.

The technical scheme of the invention is realized as follows: a surface treatment process of a copper-aluminum bimetal material comprises the following steps:

(1) hot dipping and deoiling: deoiling the copper-aluminum composite material by using SF deoiling powder, wherein the using amount is 40-60 g/L, the solution temperature is 50 +/-10 ℃, and the time is 5-8 min;

(2) washing with water: cleaning with deionized water at room temperature for 20-40 s;

(3) alkali washing: carrying out alkaline washing by adopting 40g/L NaOH solution at the temperature of 50 +/-10 ℃ for 40-80 s;

(4) washing with water: cleaning with deionized water twice at room temperature for 20-40 s;

(5) anodic oxidation: h of 200-300 g/L is adopted₂SO₄Anodizing the solution, keeping the voltage at 15-18V, keeping the temperature at 10-20 ℃, and keeping the time for 5 +/-2 min;

(6) high-temperature water sealing: carrying out high-temperature sealing treatment on the copper-aluminum composite material at the temperature of 80-95 ℃ by using deionized water for 15-30 s;

(7) washing with water: cleaning with deionized water at room temperature for 5-15 s;

(8) tin plating:tin plating is carried out on the copper-aluminum composite material by adopting 30-50 g/L of stannous sulfate and 10-20 g/L, DS g/15 g/25 g/L of brightening agent of 120-150 g/L, X g/of sulfuric acid, and the current is 0.8-1.2A/dm²The temperature is 15-25 ℃, and the time is determined according to the thickness;

(9) washing with water: cleaning with deionized water at room temperature for 5-15 s, and then cleaning with water at 50-60 ℃ once;

(10) and (3) drying: removing water stain on the surface, and baking in an oven.

The invention has the beneficial effects that: the method comprises the steps of anodizing the copper-aluminum composite bar to form a layer of compact insulating aluminum oxide on the surface of aluminum, protecting aluminum element, preventing the aluminum element from participating in a subsequent electroplating process, and activating the surface of copper at an anode; then the copper-aluminum composite bar is directly electroplated with tin, so that the procedures of zinc dipping and pre-copper plating in the middle are reduced, the electroplating protection effect is achieved, the electroplating process flow is greatly shortened, the resource consumption is reduced, the production efficiency is improved, the electroplated layer is reduced, the plating binding force is improved, and the hidden danger of plating layer damage is further reduced.

Detailed Description

For better understanding and implementation, the surface treatment process of the copper-aluminum bimetal material is described in detail as follows: selecting a horizontal continuous casting copper-aluminum composite bar with the width of 60mm, the thickness of 6mm and the length of 40mm, and carrying out the following steps:

(1) hot dipping and deoiling: deoiling the horizontal continuous casting copper-aluminum composite row by using SF deoiling powder, wherein the using amount is 48g/L, the solution temperature is 50 ℃, and the time is 6 min;

(2) washing with water: cleaning with deionized water at room temperature for 30 s;

(3) alkali washing: washing with 40g/L NaOH solution at 50 deg.C for 60 s;

(4) washing with water: cleaning with deionized water twice at room temperature for 30 s;

(5) anodic oxidation: with 220g/L H₂SO₄Maintaining the voltage of the solution at 15.5V, the temperature at 20 ℃ and the time for 5 min;

(6) high-temperature water sealing: sealing the copper-aluminum composite bar by using deionized water at the temperature of 90 ℃ for 25 s;

(7) washing with water: washing with deionized water at room temperature for 10 s;

(8) tin plating: adopting stannous sulfate 40g/L, sulfuric acid 130g/L, X brightener 15g/L, DS cylinder opening agent 20g/L, and controlling current at 1.0A/dm²The temperature is controlled at 22 ℃, and the thickness of a tin coating is 6 um;

(9) washing with water: washing with deionized water at room temperature for 10s, and washing with 55 deg.C water;

(10) and (3) drying: removing water stain on the surface, and baking in an oven to obtain the finished product.

Claims

1. A surface treatment process of a copper-aluminum bimetal material is characterized by comprising the following steps:

(8) tin plating: tin plating is carried out on the copper-aluminum composite material by adopting 30-50 g/L of stannous sulfate and 10-20 g/L, DS g/15 g/25 g/L of brightening agent of 120-150 g/L, X g/of sulfuric acid, and the current is 0.8-1.2A/dm²The temperature is 15-25 ℃, and the time is determined according to the thickness;