9. Electrode materials
Copper, graphite, copper and tungsten are used for electrode materials.
The selection guide is as follows.
- Electrode wear ratio
- Fitness for the electrode production
- Material costs
Etc.
1) Copper
Copper (Standard JIS: more than 99.96% purity) is used.
As for the temper, H which is the hardest is suitable. H material has limit of the size of the material, and for large electrodes, material around 1/2H is used.
2) Graphite
Graphite fine particles are combined by combination materials called the binder. There are a number of products with the characteristics such as graphite particle size and binder materials. On the choice of materials, not only the performance of discharge machining, cutting efficiency at the time of electrode production is also important.
3) Copper tungsten
On making fine shape electrodes, it is characterized by good machinability.
In addition, the appropriateness of electrode materials should be judged with "the material of the workpiece," "contents of discharge machining" and "method of making the electrode" and so on.