How to identify bare copper wire, tinned copper wire and copper-clad aluminum wire

Bare copper wire, tinned copper wire, copper-clad aluminum wire are widely used in braided shielding mesh, due to material differences, resulting in a mixed market for weak current cables. Copper-clad aluminum wire and bare copper wire have the same appearance color, at first glance, it is difficult to distinguish, with greater confusion. The advantages and disadvantages of various woven net materials also confuse the majority of engineering friends and cannot be identified. The following is to introduce some conventional methods to distinguish between bare copper wire, tinned copper wire and copper-clad aluminum wire.
1. Visual inspection of appearance. Stripping the outer cover of the video cable allows the tinned copper wire to be quickly identified from the three wire materials, as only the tinned copper wire is silver and the other two are yellow. Next, cut a video line vertically and neatly, look at the section of the woven mesh, if it is yellow, it is a bare copper wire; If it is white, it is copper-clad aluminum wire. The three types of thread materials for weaving nets are thus distinguished
2. Use a tool to scratch the surface of the video cable woven net, the tinned copper mesh appears yellow after scratching, the bare copper mesh is still yellow, and the copper-clad aluminum mesh appears snowflake white. The same effect can be obtained by placing the video cable woven net on a concrete floor.
3. Overfire test. Disassemble the video cable woven net, dial it to one side, close to the flame, if it is burned to form a ball-like object, it is copper; If the wire turns white after burning, and sags, it will break when touched by hand, and it is a copper-clad aluminum mesh.
Bare copper wire, tinned copper wire, copper-clad aluminum wire and their distinction copper-clad aluminum wire composition and difference: bare copper wire is a copper wire made of pure copper rod drawing, single material, copper metal on the surface, yellow in the past, and the color is dark and light due to the purity of copper. In terms of physical properties, the bare copper wire material is soft and has excellent electrical conductivity. The process of tinned copper wire is slightly more complicated than that of bare copper wire, and the pure copper rod is drawn into silk and then a thin layer of tin is plated on the surface of the copper wire by hot-dip tin plating process to become tinned copper wire. This thread has a silver appearance because tin is a silver metal. Tinned copper wire, the material is relatively soft, good electrical conductivity, compared with bare copper wire, its corrosion resistance, oxidation resistance is stronger, can greatly extend the service life of weak current cable. Copper-clad aluminum wire adopts over-wrapped welding manufacturing technology, the copper strip is concentrically coated on the outer surface of the aluminum rod core wire, and the copper layer and the core wire form a strong metallurgical bond between the atoms, so that the two different metal materials are combined into an inseparable whole, which can be drawn and annealed like a single metal wire, copper and aluminum are reduced in the same proportion during the drawing process, and the volume ratio of the copper layer remains relatively constant. The weight of copper-clad aluminum wire is very light, and the appearance is also yellow, but compared with the previous two, the conductivity is much worse, the flexibility is not enough, it is easy to break, 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 period of time.