Superiority of Graphite Electrodes for Electrical Discharge Machining

Graphite electrode 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 easy processing, high discharge machining removal rate, and 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, making them unsuitable for processing large electrodes. These factors have led to some group based spark machine customers using 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, its processing speed 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 comparing the milling time of graphite electrodes with copper electrodes, graphite is 67% faster than copper electrodes. In general, in discharge machining, using graphite electrodes is 58% faster than using copper electrodes. In this way, the processing time is significantly reduced, while also reducing manufacturing costs.

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

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 process of mold cavity polishing and chemical polishing, but still achieves the expected surface smoothness. If time and polishing processes are not increased, copper electrodes cannot produce such workpieces. In addition, graphite is divided into different grades, and appropriate grades of graphite and electrical discharge parameters can only achieve ideal machining results in specific applications. If operators use the same parameters as copper electrodes on a spark machine using graphite electrodes, the results may be disappointing. If the material of the electrode needs to be strictly controlled, graphite electrodes can be set in 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 match:

1. 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
2. Good machinability, able to achieve complex geometric shapes
3. Lightweight, with a density less than 1/4 of copper, making the electrodes easy to grip
4. The number of individual electrodes can be reduced as they can be bundled into combination electrodes
5. Good thermal stability, no deformation, and no machining burrs