EFFECT OF DIFFERENT EDM WIRE ELECTRODES ON THE MACHINABILITY OF D3 MATERIAL By Vikrant Aggarwal,Production
Abstract
Wire electric discharge machining (WEDM) is a special form of the traditional EDM process in which material is eroded from the work piece by a series of discrete sparks between the work piece and the wire electrode separated by a thin ?lm of dielectric ?uid. The movement of the wire is controlled numerically to achieve the desired three-dimensional shape and accuracy for the work piece. WEDM is used in tool and die making industries, automobiles, aerospace, nuclear, computer and electronics industries. The average cutting speed, relative machining costs, accuracy and surface ?nish have been improved since the commercial inception of the machines, much more improvement is still required to meet the increasing demand of precision and accuracy by different industries.The performance of WEDM depends much on the wire electrode used. Brass wire is used extensively as a wire electrode in WEDM. Various high performance electrodes like zinc coated, diffusion annealed, coated steel cored etc. have been developed to satisfy the machining needs. In the present study, three wires (brass wire, zinc coated wire and High Cutting Speed (HCS) wire) were selected and the performance parameters - material removal rate, wire consumption and surface roughness were studied on the machining of AISI D3.The factor analysis was used to analyse the relationship of input parameters (Pulse on time and Peak Current ) with performance characteristics (material removal rate, wire consumption and surface roughness).Result obtained shows the improvement in surface roughness with brass wire over zinc coated wire and High Cutting Speed (HCS) wire , but maximum wire consumption (117 m/ piece) was also recorded with brass wire. Material removal rate was maximum with HCS wire and minimum with brass wire. Electron Diffraction Spectrometry (EDS) results shows the deposition of wire material on the work piece. Scanning Electron Microscopy revealed the deposition of different elements wire on the surface of workpiece.
