A few years ago, it was thought that the surface quality of parts processed with graphite could only reach VDI18. However, it has been shown that the surface quality of the workpiece processed by graphite can reach VDI12 or higher grade. Of course, this standard is not for all graphite materials, or by EDM traditional situation, such as crude graphite or conventional graphite can not reach the standard. In order to obtain the surface quality, various production conditions must be in the best fit state with graphite material. In this case, the size of the electrode, the choice of the type of graphite is the key factor, will play a decisive role. However, the important point is that the use of graphite materials can achieve very fine surface quality.

　　Many manufacturers of EDM equipment and manufacturers of graphite materials have made a lot of efforts. Today, they are able to provide customers with graphite processing specific processing equipment and processing parameters. In addition, graphite producers are also relying on their more refined graphite brands to meet customer demand.

　　However, the most important factor is that people must have the right choice of EDM equipment manufacturers and graphite manufacturers. Big deal situation often appear, such as some customers to sample processing will choose the most complex parts, and then to the equipment manufacturer for testing and processing. In fact, this type of components in the customer's products accounted for up to 1%. If the EDM equipment and processes are based on this standard, then there is no doubt that there will be a problem: 99% of the other conventional processing how to do?

　　Therefore, the equipment should be used to meet the needs of the 95% types of products. The rest of the products can be entrusted to other companies specializing in the production of special processing, or the use of a multiple electrode. In this case, we can also use the method to extend the discharge time or, if necessary, the copper electrode.

　　Advantages of graphite EDM

　　Graphite also has the following advantages:

　　The processing performance (to follow the rules for operating conditions).

　　The high thermal stability (thermal deformation will happen).

　　The light weight (for processing equipment)

　　I don't have to (for this essential burr automation system).

　　The ductility coefficient is low (small temperature change).

　　It can provide the best choice for a variety of processing conditions (coarse and fine grain graphite)

　　On the market, but also provide the electrode can be used (i.e., graphite products have been processed, can be immediately applied to EDM).

　　Graphite has high temperature strength, low thermal expansion coefficient, good mach inability and good heat and conductivity, so graphite electrode is widely used in metallurgy, electric furnace, EDM and other fields. In the field of EDM, the development of new graphite electrode material and its processing technology expands the application range of EDM and improves its performance. Compared with the graphite electrode and the copper electrode has the advantages of electrode consumption, fast processing speed, good machining performance, high processing precision, small thermal deformation, light weight, high temperature resistance, easy processing, surface processing of high temperature, electrode bonding etc.. Although graphite is a very easy cutting material, but because the graphite materials used for EDM electrode must have sufficient strength to avoid damage during operation and EDM process, at the same time, electrode shape (thin, rounded, sharp change) and also put forward higher requirements on the graphite electrode and the grain size and strength, which leads to in the process of graphite work piece easily broken, the tool is easy to wear. So how to prevent the work piece from crushing, improve the surface processing quality and reduce the cost of processing tools become an important problem of graphite electrode processing. Conventional turning, milling and grinding methods can meet the demand of machining simple shape electrodes, but the requirement of electrode geometry complexity has been increasing in recent years. High speed machining high surface quality and high processing precision make graphite electrode high speed machining has become a hot spot in mold EDM processing,

　　Finishing should make the processing stable, have smaller shape error and good surface quality, at the same time the tool wear is small. Tool wear and machining costs are major considerations. In finishing machining, the influence of milling direction on machining precision and surface quality should be taken into account. In the feed milling along the surface will appear pull milling (upward knife) or drilling and milling (down knife) phenomenon, tool deformation will lead to work piece contour deviation. The contour deviation of drilling and milling is less than that of drawing and milling, and the contour deviation of reverse milling is better than that of forward milling. Therefore, considering the critical condition of tool quality and the stability and reliability of machining process, the best method of milling along the contour should be the combination of reverse milling and plane contour milling. In addition, when the milling, the envelope contour milling tool life is greater than drilling milling, reverse milling when the two almost.