# The manufacturing process of tin-plated copper-clad aluminum alloy and wire is revealed.

In the modern industrial field, tin-plated copper-clad aluminum alloy wire, as a high-performance composite metal material, is widely used in power transmission, electrical equipment and electronic products due to its excellent conductivity, corrosion resistance and mechanical strength. This article will reveal in detail the manufacturing process of tin-plated copper-clad aluminum alloy wire, from raw material preparation to finished product release, and gradually unveil its mystery.

## Preparation of 1. Raw Materials### 1.1 Preparation of Aluminum Alloy Core Wire The core of tinned copper-clad aluminum alloy wire is aluminum alloy core wire. First, high-purity aluminum is selected as the substrate, and the aluminum content is generally between 95.6 and 97.6, and appropriate amount of alloying elements such as magnesium (0.8 to 1.2), chromium (0.4 to 1.1), and manganese (0.7 to 1.3) are added to improve the mechanical properties and corrosion resistance of the aluminum alloy. These raw materials are melted at high temperature through a dual-frequency furnace and undergo precise alloying treatment to ensure the uniformity of alloy composition.

### Preparation of 1.2 Copper Strip Copper strip is used as a coating material, and its quality directly affects the conductivity and appearance of the final product. Selection of high purity electrolytic copper, through precision rolling process made of specific width and thickness of copper strip. The surface of the copper strip needs to undergo strict degreasing, cleaning and passivation treatment to ensure a good combination with the aluminum alloy core wire.

## 2. cladding and composite ### 2.1 copper strip cladding Under the protection of inert atmosphere (such as nitrogen or argon), the pretreated copper strip is evenly coated on the surface of the aluminum alloy core wire. This step is usually carried out by a continuous coating machine to ensure a close fit between the copper strip and the aluminum alloy core wire to avoid the generation of bubbles and voids.

### 2.2 composite process The composite process is a key link in the manufacture of tin-plated copper-clad aluminum alloy wire. Common compounding methods include extrusion compounding and roll compounding.

-**Extrusion compounding**: The aluminum alloy core wire covered with copper strip is assembled into an extruded blank, and then extruded by an extruder under high temperature and high pressure. This method can ensure the uniformity of metal flow and obtain good metallurgical bonding, but the production efficiency is relatively low and the mold wear is large.

-**Rolling composite**: The coated composite blank is rolled by a rotating roll, and the copper strip and the aluminum alloy core wire are tightly combined by the rolling force. Rolling composite operation is simple, equipment requirements are not high, and easy to achieve large-scale production. For some dissimilar metals with large differences in performance, warm rolling or hot rolling can be used to further improve the composite effect.

## After 3. drawing and reducing through the composite process, the obtained copper-clad aluminum alloy semi-finished product line needs to be drawn through the drawing machine for multiple times to prepare parallel wires of various specifications. In the drawing process, it is necessary to strictly control the deformation of a single pass to avoid excessive stress leading to material fracture. After drawing, annealing treatment is required to eliminate internal stress and improve the flexibility and processing performance of the material.

##4. tin plating treatment Tin plating is the last step in the manufacture of tin-plated copper-clad aluminum alloy and wire, and it is also a key step to give it excellent corrosion resistance. The tinning process usually includes the following steps:

### 4.1 pretreatment Before tin plating, the copper clad aluminum alloy wire should be thoroughly cleaned and activated to remove oil stains and oxides on the surface and improve the adhesion of the coating.

### 4.2 tin plating adopts hot-dip tin plating process. The copper-clad aluminum alloy wire is immersed in molten methyl sulfonate tin plating solution, and a uniform and dense tin layer is formed on the surface of the copper layer through chemical reaction. The tin-plated mold needs to have high precision to ensure the uniformity of the coating thickness.

### 4.3 post-treatment After tin plating, the wire needs to be polished and passivated to improve the gloss and corrosion resistance of the coating. The polishing treatment adopts mixed acid polishing liquid, and the ideal surface effect is obtained by controlling the polishing time and the number of times. Passivation treatment is to form a dense oxide film on the surface of the coating to further enhance the corrosion resistance of the coating.

##5. finished product inspection and packaging Tinned copper-clad aluminum alloy wire after tinning treatment shall be subject to strict finished product inspection, including appearance inspection, size measurement, conductivity test and corrosion resistance test, etc., to ensure that the product quality meets the standard requirements. After passing the inspection, package and mark, prepare for factory sale.