EDMing

EDMing removes material at such high temperatures that the process produces metallurgical changes in the material surrounding the cut. This article discusses the various surface effects and how they can be detected and measured. It also reviews the different methods for correcting or removing the surface flaws and roughness caused by EDMing.

This report details the results of a test of graphite electrodes. The test compared the performance and machinability of three graphite grades, ranging from an inexpensive coarse grade to a relatively costly ultrafine grade.

The more sophisticated die-sinker EDMs on the market today possess enough intelligence to monitor cutting conditions and make necessary adjustments on the fly. This article describes the technology that drives these smart machines and the "fuzzy logic" they use to maintain an optimal spark.

Graphite electrodes are extremely difficult to machine because of the material’s abrasiveness. This article explains why it takes an endmill with a CVD diamond coating and multiple flutes to cut graphite without wearing tool quickly.

Adequate flushing is needed to keep EDM wires from breaking. This article explains why wires break, and how dielectric fluid delivered with sufficient flow and pressure can prevent these failures from occurring even in less than ideal conditions.

To produce graphic electrodes for EDMing large cavities, shops sometimes must machine the piece in smaller sections and bond them together. This article explains how to build and use a bonded graphite electrode so that a ridge at the electrode’s bond line can be avoided.

Centralized mineral filtration for wire-EDM dielectric fluid can remove contaminants down to the 1-micron level and dispose of them in an environmentally responsible way. This article describes the mineral filtration process and compares it to the other common filtration methods.

With innovations in technology, EDM has found its place as a reasonable alternative to other precision machining operations. This article reviews five recent developments: the introduction of a new electrode material, operations that replace dielectric fluid with gas, the development of electro-conductive powders, the EDMing of nonconductive materials and a method for producing complex part geometries with simple electrodes.

Reliable EDM will take on any job that other shops can’t machine conventionally or cost-effectively.