ELECTRO CHEMICAL WIRE CUTTING PROCESS (ECWCP) EXPERIMENTAL FEASIBILITY AND PROCESS ANALYSIS

Abstract

In last three decades there have been rapid developments in the application of ECM techniques to production industries. In view of the rapid development and continuous research ECM is finding applications in industries such as aerospace, nuclear and in mass production industries such as automobile manufacture. However associated tool design problems particularly in ECM assisted sinking operations have been found to hinder its applications to a certain extent. In Electro Chemical wire Cutting Process (ECWCP) the work piece (anode), is dissolved electro-chemically, using a cathode in the form of fine wire (tool). The workpieces 'with different contours can be shaped by providing relative movement between the anode (work) and the wire (tool). ECWCP has advantages of (i) no requirement of tool design, (ii) small material wastage, (iii) reduced energy consumption, (i) applicability of the numerical/computer control. In view of the advantages listed above the present research work on ECWCP was undertaken with a veiw to establish its experimental viability and to conduct process analysis. The process models constructed on the basis of experimental data have been employed for the optimisation of processing parameters so as to achieve maximum metal removal rate (MRR) and minimum over cut etc. ii Survey of literature reveals that,- whereas considerable amount of work. has been done and reported on ECM, little work has been reported on ECWCP. In 1977, K. Chikamori reported about electro chemical machining in stagnant electrolyte (ECMSE) using pulsating current and established the feasibility of the wire cutting process. In 1983, K.Chikamori, H.Yamamoto and R. Maeda derived .a relationship for equilibrium inter- eleCtrode gap when pulsed current was used during the cutting of metal. They showed that a fairly good agreement between 'theoretically predicted and experimental values existed except when the table advancing rate was below 1.00 mm/minute They futher investigated into the effect of process parameters on the feed rate in wire-electrochemical machining with pulsed current. In 1988 H. El-Holy and J.A. McGough have designed and evaluated an apparatus for electrochemical arc wire Machining (Wire- ECAM). According to them the metal removal in ECAM is due to combined actions of electrochemical dissolution and erosion due to electro discharge. They could achieve metal removal rates, that were about five to fifty times greater than obtained in ECM and EDM respectively . In the present work a complete design, development: and fabrication of an experimental-rig for ECWCP 'was undertaken and the component assemblies as listed below were designed and manufactured :