What Are Copper Bars?

Copper bus bar is an indispensable conductive material for manufacturing motor windings, high and low voltage electrical appliances, switch contacts, and wires for power supply and distribution installations.

The surface quality of copper bus bar can be divided into three main aspects: surface smoothness, surface flatness and surface defects. It is related to copper properties, production process, production management and

The traditional copper bus bar production generally uses the "squeezing-drawing-annealing" process. This method has the following disadvantages:

1. The surface of the product is prone to burrs, warps, and pits, which can easily cause insulation breakdown of the transformer windings.

2. The resistivity and mechanical properties of the product are not uniform, and it is difficult to meet the requirements of impedance matching of transformers and motors.

3 Production of copper bus bars with width-to-thickness ratios greater than 10 and large cross-sectional areas is very difficult.

4 If the surface of the bare wire produced is not treated properly, the lubricant residue on the surface of the flat wire affects the adhesion quality of the paint film.

5. Equipped with different specifications according to different product needs

It can be seen from the continuous extrusion deformation principle and process that

First, ensure that the charge is dry, strengthen the melt coverage, and improve the casting process

Ensuring that the charge is dry can prevent the moisture in the charge from reacting with copper to form oxide inclusions and inhaling hydrogen; strengthening the melt cover can prevent melt inhalation

Copper bus

And oxidation, thereby preventing "hydrogen disease" or "oxygen disease" from occurring during the heat treatment of the copper bus bar, causing surface defects such as peeling, bubbles, inclusions, and other surface defects of the copper bus bar; reasonable casting process can not only maximize production efficiency, but It can reduce defects such as looseness, cracks, coarse grains, and microstructure segregation, which can reduce surface cracks, voids, and surface roughness of the copper bus bar, and improve the surface quality of the copper bus bar.

Second, strengthen production process control and production management

In order to reduce the surface defects of copper bus bars, it is important to strengthen process control and production management.

3. Pickling of copper bus bar

After the copper ingot is heated and extruded to form a copper bus bar, a large amount of copper oxide exists on the surface of the copper bus bar because of heating, which can be removed through an acid cleaning process.

Fourth, the optimal selection and reasonable use of hot extrusion die, tensile die

Copper hot extrusion molds work under severe high temperature conditions. Generally, cermet molds with both ceramic characteristics (high hardness, wear resistance, high temperature resistance, oxidation resistance, corrosion resistance) and metal characteristics (high toughness, plasticity) are used. .

The tensile die is made of a cemented carbide material containing tungsten carbide and cobalt. Optimized design of the lubricating cone, working belt, sizing belt, and exit cone of the stretching die. The holes in the stretching die are brightly polished. .

4. Process lubricant for mold stretching

Process lubricants can be divided into three categories according to the polymerization state: one is full oil and mixed oil; the other is water-based emulsion; the third is solid lubricant. Copper busbar manufacturers in the domestic copper processing industry have successfully used water-based emulsions as process lubricants. It has both the lubricity and stability of oil, as well as the cooling and cleaning properties of water, and is low in price and easy to use. In actual production, it is best to purchase a lubricant produced by a professional manufacturer. Because the lubricant contains a large amount of water, it will deteriorate easily over a long period of time. In the process of use, pay attention to maintenance and monitoring, and replace it regularly as required.

V. Surface protection during stretching, straightening and shearing

The copper extruded billet after pickling is stretched with a die. In order to protect the bright surface after stretching from scratches, bumps, and abrasions during the straightening, shearing production process or lifting and handling process, the stretched copper bus bar is stretched. Lay flat on a clean sack, with each layer separated by three parts: the head, middle and tail. ^[1]