Authors: M P Jahan M Rahman Y S Wong
Publish Date: 2011/12/01
Volume: 21, Issue: 8, Pages: 1655-1668
Abstract
Apart from the necessity of surface modification based on different applications in most of the cases diffusion of carbon or foreign particles on the workpiece surface during microelectrodischarge machining microEDM is avoidable especially in finishing microEDM This study aims to investigate different sources of materials that migrate to the machined surface during finefinishing of microEDM of cemented tungsten carbide WCCo The machined surfaces have been examined under scanning electron microscope and energy dispersive xray to investigate the changes in chemical composition It has been observed that during finishing of microEDM the major source of materials transfer to both the workpiece and electrode is the diffusion of carbon that comes from the decomposition of the hydrocarbon dielectric In addition materials from both workpiece and electrode transfer to each other based on machining conditions and discharge energy The migration occurs more frequently at lower gap voltages during diesinking with microEDM because of low spark gap and stationary tool electrode Milling microEDM results in lower amount of carbon migration and fewer surface defects that improve the overall surface finish significantly
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