Application of Graphite Electrode in EDM of Mold Manufacturing

In the 20th century, copper was widely used as electrode material in EDM. At that time, graphite materials would only be considered as alternatives when making large electrodes and the mould processing requirements are not high or rough machining. Some technicians who had been in contact with graphite electrodes in the early days had a general impression: the graphite material was dirty, easy to slag, the surface effect was not good, the processing efficiency was not high, etc.

With the development of high and new technology, the manufacturing process of graphite materials has been continuously improved. Graphite materials that can meet different EDM needs are emerging in an endless stream. Graphite high-speed milling machine tools have emerged on the market. The graphite discharge performance of CNC EDM machine tools has also been comprehensive. Promote. Today, in Europe, where manufacturing technology is leading, more than 90% of the electrode materials of mould companies use graphite. Graphite has been widely used as electrode material in moulds for aerospace, automobiles, home appliances, electronics, etc. This significant change is attributed to the advantages of graphite electrodes that can achieve high efficiency and high quality processing.

According to the characteristics of graphite materials, Graphite Electrode Manufacturer introduce you how to choose the right graphite material, electrode manufacturing and electric discharge machining.

Graphite is a non-metallic material with a very high melting point of 3 650 ℃, while the melting point of copper is 1083 ℃, so graphite electrodes can withstand greater current setting conditions. The greater the scaling of the discharge area and the electrode size, the more significant the superiority of high-efficiency rough machining of graphite materials.

Graphite Electrode

The Graphite Electrode has the characteristics of being able to withstand high current conditions. In addition, under the appropriate rough machining setting conditions, the ablation produced by the steel workpiece containing carbon elements during processing and the carbon in the decomposition of the working fluid generated at high-temperature Particles, under the effect of polar effects, part of the erosion and carbon particles will adhere to the surface of the electrode to form a protective layer, ensuring that the graphite electrode has very little loss during roughing, even "zero loss".

The thermal expansion coefficient of the graphite material is small, and the thermal expansion coefficient of the copper material is four times that of the graphite material. Therefore, the graphite electrode is less likely to be deformed than the copper electrode during electrical discharge machining, and more stable and reliable processing accuracy can be obtained.

The density of graphite material is lower than that of copper. The weight of graphite electrode of the same volume is only 1/5 of that of copper electrode. It can be seen that the larger volume electrode is very suitable for using graphite material, which greatly reduces the load of the spindle of the EDM machine. The electrode will not cause problems such as inconvenient clamping and deflection displacement during processing due to the large weight. It makes sense to use graphite electrodes.

The graphite material has good adhesiveness. The electrode can be milled and discharged by using conductive adhesive to bond the graphite to the fixture, which can save the process of processing screw holes on the electrode material and save working time. The graphite material is relatively brittle, especially the small, narrow and long electrodes, which are easily broken when subjected to external forces during use, but you can immediately know that the electrode has been damaged. If it is a copper electrode, it will only bend and not break. This condition is very dangerous and difficult to find during use, and it is easy to cause the workpiece to be scrapped.

China Graphite Electrodes, you are welcome to contact us.