Modelling of Electrochemical arc Machining by Use of Dynamic Data Systems

Abstract

Electrochemical Arc Machining (ECAM) attains high metal removal rates by combining the mechanisms of electrochemical dissolution (ECD) and electrodischarge erosion (EDE). ECD and EDE occur as discrete phases of randomly-varying intensity and duration. Metal removal in the leading and side-gaps of ECAM drilling is discussed. The random occurrence of spikes in both working voltage and machining power that arise during the ECD and EDE phases is described in terms of stochastic difference equations which are obtained from the Dynamic Data Systems (DDS) modelling method. The spectral moments of the voltage and power profiles developed from these models are used to discriminate between the phases of ECD, and the occurrence arcs and aparks in the machining gap. ECAM-drilling is used to illustrate how the influences on the type, intensity and duration of the machining phases can be studied. The analysis of the machining power is shown to be useful only for qualitative assessments.