No abstract

Electrical Discharge Machining (EDM) is a non-conventional machining process widely used to manufacture hard material components which are not easily machined by conventional machining processes. Several modeling approaches have since long been proposed to characterize the EDM process, based on the electro-thermal phenomena that occur. Several of these early models are analytical models that have the major advantage of providing predictions of process performance based on analytical solutions. Unfortunately, their derivation often demands a number of assumptions and simplifications, which can limit the scope and precision of the predictions obtained. Two of the most known analytical models are based on different heat sources: a point heat source [1], and a uniform disk heat source [2]. In this paper, these two analytical EDM models are analyzed and compared with more elaborated numerical models in which specific modeling assumptions are lifted; the objective is to quantify the influence of each of these assumptions on the final result. Numerical simulations are based on the finite element method, which enables to study the influence of different temporal pulse shapes, the spatial intensity distribution, the temperature dependency of the thermal coefficients, and in particular the influence of the way latent heat is taken into account. The results are analyzed in terms of the predicted material removal rate (MRR), depth and radius of the crater. A comparison is presented between the two theoretical results [1], [2], and those obtained by the more elaborated numerical models. At the same time, a comparison is also made with some experimental data from literature.

No abstract