Ultra-high power graphite electrodes, by replacing copper electrodes with graphite electrodes for mold manufacturing, significantly shorten the mold manufacturing cycle, enhance labor productivity, and reduce the mold manufacturing cost. In recent years, with the introduction of precision molds and high-efficiency molds (with increasingly shorter mold cycles), people’s requirements for mold production have been getting higher and higher. Due to the various limitations of copper electrodes themselves, It has increasingly failed to meet the development requirements of the mold industry. Graphite, as an EDM electrode material, has been widely used in the mold industry due to its advantages such as high machinability, light weight, fast forming, extremely low expansion rate, low loss and easy dressing. It is inevitable that it will replace copper electrodes.
1. Characteristics of Graphite Electrode Materials
CNC machining features fast processing speed, high machinability and easy dressing. The processing speed of graphite machines is 3 to 5 times that of copper electrodes, and the precision processing speed is particularly outstanding. Moreover, its strength is very high. For ultra-high (50 to 90mm) and ultra-thin (0.2 to 0.5mm) electrodes, they are not prone to deformation during processing. Moreover, in many cases, products need to have a very good texture effect. This requires that when making electrodes, they should be made as integral male electrodes as possible. However, there are various hidden corner clearings during the production of integral male electrodes. Due to the easy trimming property of graphite, this problem can be easily solved and the number of electrodes can be greatly reduced, which copper electrodes cannot achieve.
2. Rapid EDM forming, small thermal expansion and low loss: Due to the better electrical conductivity of graphite than that of copper, its discharge rate is faster than that of copper, being 3 to 5 times that of copper. Moreover, it can withstand a relatively large current during discharge, which is more advantageous for rough electrical discharge machining. Meanwhile, under the same volume, the weight of graphite is 1/5 times that of copper, which greatly reduces the load of EDM. It has great advantages in manufacturing large electrodes and integral male electrodes. The sublimation temperature of graphite is 4200℃, which is 3 to 4 times that of copper (the sublimation temperature of copper is 1100℃). At high temperatures, change
Ultra-high power graphite electrode
It is extremely small in shape (1/3 to 1/5 of copper under the same electrical conditions) and does not soften. The discharge energy can be transferred to the workpiece efficiently and with low consumption. Because the strength of graphite actually increases at high temperatures, it can effectively reduce the discharge loss (the loss of graphite is 1/4 of that of copper), ensuring the processing quality.
3. Light weight and low cost: In the production cost of a set of molds, the CNC machining time, EDM time, and electrode wear of the electrodes account for the vast majority of the total cost, and all these are determined by the electrode material itself. Compared with copper, the machining speed and EDM speed of graphite are both 3 to 5 times that of copper. Meanwhile, the feature of minimal wear and the production of the integral graphite electrode can both reduce the number of electrodes, thereby reducing the material consumption and machining time of the electrodes. All of these can significantly reduce the production cost of molds
2. Requirements and Characteristics of Mechanical and Electrical Processing of Graphite Electrodes
1. The production of electrodes: Professional graphite electrode production mainly uses high-speed machine tools for processing. The machine tools should have good stability, with uniform and stable three-axis movements without vibration. Moreover, the rotational accuracy of components like the main shaft should also be as good as possible. The electrode can also be processed on general machine tools, but the process of writing the tool path is different from that of copper electrodes.
2.EDM electrical discharge machining graphite electrodes are carbon electrodes. Because graphite has good electrical conductivity, it can save a lot of time in electrical discharge machining, which is also one of the reasons why graphite is used as an electrode.
3. Processing Characteristics of Graphite Electrodes: Industrial graphite is hard and brittle, causing relatively severe wear on tools during CNC machining. Generally, it is recommended to use tools coated with hard alloy or diamond. When rough machining graphite, the tool can be directly placed on and off the workpiece. However, during finish machining, to prevent chipping and cracking, a light tool and fast traverse method is often adopted.
Generally speaking, graphite rarely breaks when the cutting depth is less than 0.2mm, and a better surface quality of the side wall can also be obtained. The dust generated during CNC machining of graphite electrodes is relatively large and may invade the guide rails, lead screws and spindles of the machine tool, etc. This requires that the graphite processing machine tool has corresponding devices for dealing with graphite dust, and the machine tool’s sealing performance should also be good because graphite is toxic. Graphite powder is a substance that is highly sensitive to chemical reactions. Its resistivity changes in different environments, meaning its resistance value varies. However, there is one thing that remains constant: graphite powder is one of the excellent non-metallic conductive materials. As long as the graphite powder is kept in an insulating object without interruption, like a thin thread, it will still be electrified. But what is the resistance value? There is no definite figure for this value either, because the fineness of graphite powder varies, and the resistance value of graphite powder used in different materials and environments will also be different.
You may not know that high-purity graphite powder also has conductive uses:
Generally, rubber is insulating. If electrical conductivity is required, conductive substances need to be added. Graphite powder has excellent electrical conductivity and lubricating demolding properties. Graphite is processed into graphite powder, which has excellent lubricating and conductive properties. The higher the purity of the graphite powder, the better its conductive performance. Many special rubber product factories need conductive rubber. Then, can graphite powder be added to rubber to conduct electricity? The answer is yes, but there is also a question: What is the proportion of graphite powder in rubber? Some enterprises use a proportion of no more than 30%, which is applied to wear-resistant rubber products such as car tires, etc. There are also special rubber factories that use a proportion of 100%. Only such products can conduct electricity. The basic principle of conductivity is that the conductor cannot be interrupted, just like a wire. If it is interrupted in the middle, it will not be electrified. The conductive graphite powder in conductive rubber is the conductor If the graphite powder is blocked by insulating rubber, it will no longer conduct electricity. Therefore, if the proportion of graphite powder is too low, the conductive effect is likely to be poor.
Graphite powder is a substance that is highly sensitive to chemical reactions. Its resistivity changes in different environments, meaning its resistance value varies. However, there is one thing that remains constant: high-purity graphite powder is one of the excellent non-metallic conductive materials. As long as the graphite powder is kept in an insulating object without interruption, like a thin thread, it will still be electrified. But what is the resistance value? There is no definite figure for this value either, because the fineness of graphite powder varies, and the resistance value of graphite powder used in different materials and environments will also be different.
Post time: May-09-2025