A mathematical model to choose effective cutting parameters in electroerosion, EDM

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introduction

Machining by electroerosion experienced a significant development during the last decades when several problems were caused following the metallographic and mechanical change of the machined surface. Several research tasks are interested in the study of optimization and the improvement of the various performances of machining by electroerosion in order to improve the productivity and the precision of machining according to the various cutting parameters. Machining by electroerosion, like any other process, presents metallurgical effects (Heat Affected Layer), it is characterized mainly, by three technical criteria: material removal, the surface quality and the relative wear of electrode - tool. The removal of material is caused mainly by a thermal phenomenon, by fusion and vaporization of metal [1].

strategy of the study

This work is interested in the study of the effect of the
selected cutting conditions: current of discharge and electrical
resistance of the electrode, on each performance: the surface
quality can be explained by the measurement of average
roughness Ra and the material flow calculated according to the
Equation (1)



Experimental - modeling


It should be noted here that to determine the mathematical models, only parameters A and B have been taken into account and neglected their interaction AB, since it is either non significant or an negligible effect regarding to A and B. By using the napierian logarithm of the natural factors and the results of the tests, allows us to determine a mathematical model according to the linear model of the Equation (4), and according to the Taguchi method.