Note: Graphite electrodes for electrical discharge machining, also known as copper electrodes

1: The increasing complexity of mold geometry and the diversification of product applications have led to higher requirements for the discharge accuracy of spark machines. The advantages of graphite electrodes are that they are easy to process, have a high discharge machining removal rate, and have low graphite loss. Therefore, some group based spark machine customers have abandoned copper electrodes and switched to graphite electrodes. In addition, some special shaped electrodes cannot be made of copper, but graphite is easier to form, and copper electrodes are heavier and not suitable for processing large electrodes. These factors have led some group based spark machine customers to use graphite electrodes.

2: Graphite electrodes are easier to process and have a significantly faster processing speed than copper electrodes. For example, using milling technology to process graphite is 2-3 times faster than other metal processing and does not require additional manual processing, while copper electrodes require manual grinding. Similarly, if high-speed graphite machining centers are used to manufacture electrodes, the speed will be faster, the efficiency will be higher, and there will be no dust problem. In these machining processes, selecting tools with appropriate hardness and graphite can reduce tool wear and copper damage. If we compare the milling time of graphite electrodes with copper electrodes, graphite is 67% faster than copper electrodes. In general, in electrical discharge machining, using graphite electrodes is 58% faster than using copper electrodes. In this way, processing time is significantly reduced, while manufacturing costs are also reduced.

3: The design of graphite electrodes is different from that of traditional copper electrodes. Many mold factories usually have different reserved amounts for rough and precision machining of copper electrodes, while graphite electrodes use almost the same reserved amount, which reduces the number of CAD/CAM and machine processing times. This alone is enough to greatly improve the accuracy of mold cavities.

Of course, after the mold factory switches from copper electrodes to graphite electrodes, the first thing to be clear about is how to use graphite materials and consider other related factors. Nowadays, some group based spark machine customers use graphite for electrode discharge machining, which eliminates the processes of mold cavity polishing and chemical polishing but still achieves the expected surface smoothness. Without increasing the time and polishing process, copper electrodes cannot produce such workpieces. In addition, graphite is classified into different grades, and using appropriate grades of graphite and electrical discharge parameters in specific applications is necessary to achieve ideal machining results. If operators use the same parameters as copper electrodes on a spark machine using graphite electrodes, the results will definitely be disappointing. If the material of the electrode needs to be strictly controlled, graphite electrodes can be set to a non loss state (loss less than 1%) during rough machining, but copper electrodes are not used. Graphite has the following high-quality characteristics that copper cannot compare to:

Processing speed: High speed milling and rough machining are three times faster than copper; High speed milling precision machining is 5 times faster than copper

Good processability, capable of achieving complex geometric shapes

Lightweight, with a density less than 1/4 of copper, the electrode is easy to clamp

Can reduce the number of individual electrodes as they can be bundled together to form composite electrodes

Good thermal stability, no deformation or machining burrs