There are many kinds of graphite products, such as ordinary graphite, impregnated graphite, fine graphite, high purity graphite, isostatic graphite, and a very special kind of graphite, that is, electric spark, graphite, or EDM graphite!

　　EDM graphite is mainly used in the production of dies. It has excellent properties that copper metal can not match. The electric spark graphite itself has the characteristics of non-metallic material, and it also has some characteristics of metal. Electric spark graphite density is smaller than copper, light quality, can bring many benefits to production; easy processing; from hardness, electric spark graphite is 1/3 of copper metal; and conductivity is less than metal copper;

　　The high temperature resistance of electric spark graphite is better than that of copper metal. The melting point of copper is more than 1300 degrees, while the melting point of electric spark graphite is about 3800 degrees. High melting point can be greatly reduced, after the electronic pulse produced by a large number of high temperature, so that melting itself, causing sublimation phenomenon. In addition, the electric spark graphite processing is simple, and the production speed is fast, and the production capacity is not to be worried!

　　EDM is a new processing technology in machinery manufacturing industry, EDM of many high hardness metal processing, and processing of complex shape, high precision parts, can be used as a tool for the anode copper material, also can use graphite materials. As a tool for EDM, the graphite material of electrode must have the following conditions:

　　(1) the structure is compact and the tissue is homogeneous; there should be no coarse particles and large pores;

　　(2) with high mechanical strength and good processability, it can work out complex shapes or sharp angles and flakes;

　　(3) the graphite tool electrode has a certain loss in the process of EDM, and this loss should be as low as possible;

　　(4) the discharge characteristics are stable and the processing speed is faster. Therefore, graphite with fine grain structure or graphite with fine particle structure is generally used in EDM, and the physical properties of graphite are best isotropic. Therefore, the graphite material with fine grain structure is the most popular graphite material used in China's electrical discharge machining.

　　In 2005, the domestic needs of EDM graphite is estimated to be 4000T, of which about 25% of high-grade graphite is used, and about 75% of middle and low-grade graphite is used. It is likely to rise by an annual increase of 10%. The use of imported high-grade graphite (mainly isostatic molding of isotropic graphite), accounting for about 10% of the total amount. There are many kinds of isotropic graphite for EDM abroad. They can be used in rough, semi finish, finish machining, fine machining, super fine machining and precision machining (line cutting, etc.).

　　EDM with graphite electrode, also known as copper, in the mold manufacturing now has many areas, graphite cost advantage plays an important role in modern processing methods, including EDM graphite (isotropic isostatic graphite) in EDM is most widely used. My company after years of application in the field of EDM graphite operation, selection of several domestic and foreign high-quality carbon materials manufacturers as partners, to provide customers with excellent products of graphite electrode in EDM process in all kinds of bad, such as carbon, loss, surface is not up to the performance parameters of material and spark machine requirements and so on bad phenomenon and graphite itself has a direct connection, high quality graphite spark machine is not any brand of imported can achieve the desired effect, my company after years of research, according to the current market mainstream equipment to customers for graphite materials with the highest price, and a professional engineer to provide professional counseling can effectively reduce the cost of operating machine, help the mold manufacturing enterprises.

　　1: the increasing complexity of the mold geometry and the diversification of product applications lead to the increasing demand for the discharge accuracy of the EDM machine. Graphite electrode has the advantages of easy processing, high removal rate and low graphite loss. Therefore, the metal electrode is replaced by graphite electrode. In addition, some of the special shape of the electrode can not use copper production, but graphite are more easily formed, and the copper electrode is heavy, not suitable for processing large electrode, these factors have caused some qunji spark machine application of graphite electrode.

　　2: the graphite electrode is easier to process, and the processing speed is faster than the copper electrode. For example, the use of milling process graphite, its processing speed is faster than other metal processing 2 ~ 3 times and does not require additional manual processing, and the copper electrode is the need for hand grinding. Similarly, if the use of high-speed graphite processing center graphite electrode manufacturing electrode, the speed will be faster, more efficient, will not produce dust problems. In these processes, the choice of the right tools and graphite can reduce the wear and wear of copper and copper. If the graphite electrode and the copper electrode graphite electrode milling time is compared, the graphite is 67% faster than the copper electrode, in general, the processing of the graphite electrode is faster than that of the copper electrode by the use of the copper electrode, and the graphite electrode is more than 58%. In this way, the processing time is greatly reduced, and the manufacturing cost is reduced.

　　3: the graphite electrode is different from the traditional copper electrode. Many mold factory usually reserved in different copper electrode roughing and finishing, and the graphite electrode is used for almost the same, which reduces the number of CAD/CAM and the single machine, for this reason, to improve the accuracy of mold cavity to a great extent. Of course, mold factory made of copper electrode to the graphite electrode, first of all should be clear is how to use graphite materials and its consideration

　　His related factors. Today, some customers use graphite electrode discharge, which eliminates the mold cavity polishing and chemical polishing process is still able to achieve the desired surface finish. It is not possible to produce such a workpiece without increasing the time and polishing process. In addition, graphite is divided into different levels, using the appropriate level in the specific application of the graphite and EDM parameters to achieve the desired processing results, if the operators use the same parameter with copper electrode in EDM using graphite electrode, then the result would be disappointing. If the material of the electrode is strictly controlled, the graphite electrode can be arranged in a non loss state (less than 1%) when being processed, but the copper electrode is not used.

　　Graphite has the following copper incomparable quality characteristics:

　　* processing speed: high speed milling roughing 3 times faster than copper; high speed milling finishing copper faster than 5 times

　　* good machinability, can achieve complex geometric modeling

　　* light weight, density less than 1/4 of copper, easy to hold electrode

　　* can reduce the number of individual electrodes, because can be bundled into a combination electrode

　　* good thermal stability, no deformation, no burr.

　　application field

　　Carbon and graphite products are widely used in various fields of machinery, electronics, semiconductor, silicon, metallurgy, petroleum, chemical, textile, electrical appliances, motor, electric, transportation, communications, aviation, atomic energy, medicine, food, biological engineering, in order to give full play to the characteristics and potential of our company has been positive for customers in different fields provide technical support and service.

　　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).

　　Mold in the home appliances, automotive, electrical, aerospace and other industrial areas has increasingly become the main process of industrial production, the main process equipment, and bear the 60%-90% of these industries in the production of parts and components of the processing. In recent years, high speed milling has broken through the limitation of traditional milling hard, high strength and high toughness die materials. But electric discharge machining with high machining accuracy and surface quality, wide processing range, especially in high speed milling can match in the advantage of joints, high hard materials of the mould cavity machining of complex and precise, thin-walled, narrow, so in electrical discharge machining (EDM) will still be the main means of the mold cavity processing. Because the graphite electrode (compared with copper) electrode consumption less, electrical discharge machining speed, good machining performance, light weight, heat expansion coefficient and other advantages, and gradually replace the copper electrode to become the mainstream of the EDM electrode. Compared with copper, graphite electrode has the advantages of less consumption, high discharge speed, light weight and small thermal expansion coefficient. Therefore, it is the main. In contrast, graphite electrode material has the following advantages:

　　Speed: Graphite discharge faster than copper 2-3 times, the material is not easy to deform, in the processing of thin reinforced electrode have obvious advantages, copper softening point in 1000, easily due to thermal deformation and graphite sublimation temperature is about 36.5 degrees, compared with, graphite material thermal expansion coefficient only copper 1 / 30.

　　Light weight: the density of graphite is only copper 1/5, large electrode discharge machining, can effectively reduce the burden of machine tool (EDM), more suitable for large-scale mold application;

　　Low loss: due to the spark oil containing C atoms, in the discharge process, the high temperature led to the C atoms in the spark oil is broken down, and the surface of the graphite electrode to form a protective film, the loss of the graphite electrode;

　　No burr: copper electrode in the end of the process, it is necessary to manually remove the burr, and graphite processing without burr, which not only saves a lot of cost and manpower, but also easier to achieve automated production;

　　Easily Polished : because of the cutting resistance of graphite copper is only 1/5, more easily by hand grinding and polishing operation;

　　Low cost: as a result of rising copper prices in recent years, now, the price of the isotropic graphite is lower than that of copper; under the same volume of graphite products price than copper low 30 to 60 percent, relatively stable prices, short-term price fluctuations relatively speaking, is relatively small.

　　Graphite mould processing technology

　　First it from mold design personnel according to the requirements of the use of products (parts), the mold structure design, plotted drawings again by skilled workers according to the requirements of the drawings by a variety of mechanical processing (such as a lathe, planer, milling machine, grinder, EDM, wire cutting and other equipment) do a good job in each part of the die, then assembled debugging until they were able to produce qualified products.

　　Present situation and development of graphite mould

　　Now graphite mould industry of human living and development plays a vital role, many industrial departments, such as Electromechanical, automobile, light industry, home appliances, electrical appliances, communication, ordnance, the development of dependence in Die & mold industry technology improvement and development, all countries in the world have invested large amount of human and financial resources to develop the graphite mold industry. Like Germany, Japan Toyo SGL in the international carbon graphite mould industry has played a leading role. The development of mold industry in our country has attached great importance to, level of mold production technology level has become the measure of a national product manufacture level of an important symbol of, because the mold in a large extent determines the product quality, efficiency and new product development capability. From 1997 in our country, the relevant departments began to pay attention to and support the development of graphite mold industry, vigorously support the graphite mold industry in the development of local enterprises in China, has now made good achievements, and made contribution to China's export earnings. For the future development of the mold industry trends, who can in the shortest time to complete the production of mold, who won the customer, to win the market. Graphite mold (graphite electrode) with its superior performance in various aspects, has established an important leading position in the mold industry and the future development trend.

　　In twentieth Century, copper was widely used as electrode material in EDM. At that time, only in the production of large electrodes and mold processing requirements are not high or rough machining, graphite materials will become an alternative. Some of the early contact with the graphite electrode of the technical staff has a general impression: dirty, surface effect is not good, the processing efficiency is not high and so on. With the development of high and new technology, and constantly improve the manufacturing process of graphite material, it can satisfy different EDM demand of graphite materials emerge in an endless stream, market graphite for high speed milling machine tool arises at the historic moment, numerical control electric spark machine tool graphite discharge performance also promotes in the round. Today, in the manufacturing technology leader in Europe, more than 90% of the electrode materials used in die and mold. Aerospace, automotive, home appliances, electronics and other mold has a large range of graphite as the electrode material, this significant

　　Owing to the high efficiency and high quality processing of graphite electrode, the change is attributed to the advantages of the graphite electrode.The choice of graphite electrode materials for electrical discharge machining (EDM) for graphite materials, mainly has the following 4 indicators directly determine the performance of the material: (1) the average particle diameter of the material. The average particle diameter of the material directly affects the state of the discharge of the material. Graphite materials the average particles smaller, more uniform material discharge, the discharge condition is more stable, surface quality is better, loss is small; average particle size is large, in the rough machining can get higher removal rate, but finishing surface effect is poor and electrode loss is relatively large. (2) the bending strength of the material. The bending strength of the material is a direct reflection of the strength of the material, showing the close degree of the internal structure of the material. The high strength of the material, the loss of its discharge performance is relatively good, on the high accuracy of the electrode, as far as possible to choose a higher strength of the material. (3) the shore hardness of materials. The hardness of graphite is higher than that of metal material, and the loss of cutting tool is larger than that of cutting metal. At the same time, the high hardness of the graphite material in the discharge loss control is good. (4) the inherent resistivity of the material. Inherent resistivity of the larger graphite material, the discharge rate will be smaller than the resistivity of the slow. The higher the inherent resistivity, the smaller the electrode loss, but when the inherent resistivity is high, the discharge

　　The stability will be affected.

　　Beijing Great Wall Co., ltd is a leading company of graphite product. We always offer the best quality and the competitive price for our customer. We are looking forward to your enquiry and cooperation in the future.

　　In twenty Century, copper was widely used as electrode material in EDM. At that time, only in the production of large electrodes and mold processing requirements are not high or rough machining, graphite materials will become an alternative. Some of the early contact with the graphite electrode of the technical staff have a general impression: the graphite material is dirty, surface effect is not good, the processing efficiency is not high, etc.. With the development of high and new technology, and constantly improve the manufacturing process of graphite material, can satisfy different EDM demand of graphite materials emerge in an endless stream, market graphite for high speed milling machine tool arises at the historic moment, numerical control electric spark machine tool graphite discharge performance also promotes in the round. Nowadays, in the manufacturing technology leader in Europe, more than 90% of the electrode materials by graphite mould enterprises. Aerospace, automotive, home appliances and electronic mould has been widely using graphite as the electrode material, the significant

　　Due to the change of the graphite electrode has many advantages such as high efficiency and high quality processing.

　　Graphite is a kind of non metallic materials, the melting point is very high, up to 3650 degrees Celsius, and the melting point of copper is 1083 degrees Celsius, so the graphite electrode can withstand greater current setting conditions. When the discharge area and the size of the electrode is larger, the advantage of high efficiency and rough machining of the graphite material is more significant. The thermal conductivity of graphite is 1/3, the heat energy produced during the discharge process can be more effective in the removal of metal materials, and therefore, in the finishing process, the machining efficiency is higher than that of the copper electrode.