Abstract
EDMed (Electric Discharge Machined) surfaces are unique in their appearance and metallurgical characteristics, which depend on different parameter such as electric parameters, flushing method, and dielectric type. Conventionally, in static workpiece method the EDM (Electric Discharge Machining) is performed by submerging both of the tool and workpiece in dielectric liquid and side flushing is provided by impinging pressurized dielectric liquid into the gap. Another flushing method has been investigated in this study, in which, instead of side flushing the rotation motion is provided to the workpiece. Surface characteristics for both flushing methods are determined and compared in this study. The investigated surface characteristics are: surface roughness, crater size, surface morphology, white layer thickness and composition. These investigations are performed using optical and SEM (Scanning Electron Microscope). Statistical confidence limits are determined for scattered data of surface roughness. It is found that the white layer thickness and surface roughness are directly proportional to discharge current for both flushing methods. The comparison has shown that the side flushing of statics workpiece gives thicker white layer and lower surface finish as compared to the flushing caused by the rotation of workpiece.
Highlights
During EDM, thermal energy generated by electric sparks is used to melt the material from surface of workpiece
The generated surfaces by the above mentioned methods are compared by surface characteristics i.e. Surface morphology, crater diameter, morphological observations, white layer thickness, and chemical composition
The integrity of EDMed surface is evaluated by morphological examinations, white layer thickness, crater size, roughness and chemical composition of the white layer
Summary
During EDM, thermal energy generated by electric sparks is used to melt the material from surface of workpiece. Dielectric liquid preserve the fluid temperature much below the flash point [2] and cools down the workpiece and tool material after each discharge. It is believed by many researchers [3,4,5] that only a small portion of the molten material is swept whereas residue material resolidified on the surface forming a so-called layer having characteristics. In present study, EDMed surfaces of aluminum alloy 2024 T6 by two different flushing methods are compared. The generated surfaces by the above mentioned methods are compared by surface characteristics i.e. Surface morphology, crater diameter, morphological observations, white layer thickness, and chemical composition
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
