Influence of the Anode Material and the Flushing Gas on the Dry Electrical Discharge Machining Process

In the last years dry electrical discharge machining (DEDM) has been proposed as an alternative to the traditional EDM. The main reason for these efforts is the absence of a liquid dielectric which results in a simpler and environmentally friendly process. This paper presents measurements of the material removal rate in function of different tool electrodes, work piece materials and flushing gases put in relation with the breakdown behavior of the process. Evaluation of absolute and current specific material removal rate are presented. The data show a big influence on the material removal rate depending on the combination of work piece material and flushing gas. Two different effects are observed, the first enhancing the removal per spark and the second one reducing the short circuiting occurrence. The share of these two effects on the enhancing of the absolute material removal rate also differs in function of the work piece material. It is suggested that the chemical reaction strongly influences the process in two different ways, on one hand releasing a surplus of energy and on the other hand changing the debris particles’ properties.