There has been a long-standing debate about whether graphite or copper is a better EDM electrode material for aerospace applications.

For this reason, Erodex has taken a closer look at the differences between the two materials and outlined reasons why graphite is likely to be the most appropriate for aerospace EDM needs.
Due to the wide range of graphite materials available, it is proven that some EDM grades are more economical than copper. Furthermore, most comparisons do not consider the cost of machining the electrode. Significant cost savings can be made choosing graphite over copper, generated through reduced machining times and speed of cut, less production time to create electrodes, faster EDM times and better throughput from EDM machines.
Graphite also offers a wide range of material characteristics in order to allow matching of the electrode material properties to the EDM application.
In addition, it should be noted that copper does not have the ability to handle current density as effectively as graphite, which performs exceptionally well at a high current density (even with complex geometry), allowing for various intricate machined details to be designed on the same electrode. The result is that the number of electrodes required to perform a job is reduced significantly.
Further reasons to select graphite over copper electrodes for aerospace applications include EDM performance, whereby graphite is able to achieve electrode wear of less than 1% in relation to the depth of cut, while working to more aggressive machine parameters. Moreover, fine-grain graphite electrodes are able to deliver similar surface finishes to that of copper, while offering much faster speeds and less wear.
For further information www.erodex.com