Bare copper wire / tinned copper wire /copper clad aluminum wire composition and difference

Bare copper wire, tinned copper wire and copper clad aluminum wire are often used in the production of security cables, which can be used for braiding coaxial cable and shielded sheathed wire.
The bare copper wire is a copper wire drawn from a pure copper rod. The material is single, and the surface is made of copper metal. The exterior is yellow in appearance, and the color is deep and shallow due to the purity of copper. Physical properties, bare copper wire material is soft, excellent electrical conductivity.
The tin-plated copper wire process is slightly more complicated than the bare copper wire. After the pure copper rod is drawn into a wire, a thin layer of tin is plated on the surface of the copper wire by a hot tin plating process to become a tinned copper wire. This line is silver in appearance because tin is silver metal. Tinned copper wire is softer in material and has good electrical conductivity. Compared with bare copper wire, it has stronger corrosion resistance and oxidation resistance, which can greatly extend the service life of weak electric cables.
The copper clad aluminum wire adopts the cladding welding manufacturing technology, and the copper strip is concentrically coated on the outer surface of the aluminum core wire, and a strong atomic metallurgical bond is formed between the copper layer and the core wire, so that two different The combination of metal materials becomes an inseparable whole, which can be drawn and annealed like a single wire. During the drawing process, copper and aluminum are reduced in proportion, and the volume ratio of the copper layer remains relatively constant. The copper clad aluminum wire is light in weight and yellow in appearance, but the conductivity is much worse than the former two, the flexibility is not enough, the breakage is easy, and the corrosion resistance and oxidation resistance are relatively low. If the copper clad aluminum production process is not well controlled, then the copper clad aluminum finished product is likely to become a pile of waste in a short time.
The structure of the three wire materials is as follows:
Bare copper wire, tinned copper wire, and copper clad aluminum wire are widely used in braided screen meshes, and the weak wire cable market is mixed due to material differences. The appearance of the copper clad aluminum wire and the bare copper wire are the same. At first glance, it is difficult to distinguish and it is extremely confusing. All kinds of woven mesh materials are superior and inferior, and they also make the majority of engineering business friends feel confused and unable to identify. Here are some general methods for distinguishing bare copper wire, tinned copper wire and copper clad aluminum wire. Taking the video line SYV75-5 woven mesh as the detection object, the following methods can be used:
1. Visually look at the appearance. Stripping the video line can quickly identify the tinned copper wire from the three wire materials because only the tinned copper wire is silver and the other two are yellow. Next, cut a video line vertically and neatly to see the cross section of the woven mesh. If it is yellow, it is a bare copper wire: if it is white, it is a copper clad aluminum wire. The wire materials of the three woven meshes are then distinguished.
2. Scratch the surface of the video cable with a tool, the yellow tinned copper mesh will appear yellow, the bare copper mesh will still be yellow, and the copper-clad aluminum mesh will appear white. The same effect can be obtained by rubbing the video wire woven mesh on the concrete floor.
3. Over-fire test. Disassemble the video wire woven mesh, and turn it to one side, close to the flame. If it is formed by burning, it will be copper material; if the wire is burned, it will turn white, and the sag will be broken when touched by hand. Copper clad aluminum mesh.
In addition, weighing with a balance, using professional electrical testing equipment to detect the electrical resistivity of the woven mesh, or using aging equipment to detect the oxidation resistance of the woven mesh is a good way to detect the woven mesh material.
Through the above introduction, we can find that bare copper wire and tinned copper wire are good materials for braided shielding mesh. In terms of oxidation resistance, tinned copper wire performs better. In terms of cost, due to the high price of tin, the cost of tinned copper wire is higher than that of bare copper wire, and the price of aluminum is very low. Therefore, the cost of copper clad aluminum wire is the lowest, and it can occupy the low-end cable market because of its low price advantage. Moreover, the copper-clad aluminum woven mesh and the bare copper mesh are difficult to distinguish, and the market is often shoddy, because the copper-clad aluminum wire has low oxidation resistance and is perishable, resulting in frequent rework of the project and causing huge losses. In the high-end cable market, tinned copper wire is the first choice for the production of branded cable.