Surface Texture and Elemental Characterization of High Aspect Ratio Blind Micro Holes on Different Materials in Micro EDM

摘要

Micro features machined through micro electrical discharge machining (micro EDM) are adversely affected by tool wear. Tool electrode and machined parts are deformed due to stochastic behaviour of discharge processes. Deposition of tool electrode material on workpiece deteriorates the surface quality of the micro part. Study of the surface quality of blind micro hole is very difficult in non-destructive method due to its miniature size. In this communication, attempts have been made to study the surface quality of high aspect ratio blind micro holes by opening the holes in destructive method. High aspect ratio blind micro holes were drilled in wear resistant high grade steel (block gauge material), zirconium based bulk metallic glass (BMG) Vit 1, titanium super alloy Ti-6A1-4V, oxygen free high thermal conductivity (OFHC) copper, Monel 400 and hard anodized aluminium alloy 6082 T6 in micro EDM by cylindrical tungsten (W) electrode and opened the holes axially through wire EDM (WEDM) to study the surface texture of the opened holes using 3D optical profilometry technique. Elemental analysis of materials of tips of tool electrode and surfaces of the opened micro holes were studied by using energy dispersive X-ray spectroscopy (EDS) technique in scanning electron microscope (SEM). Deformations of tool electrode and tool profile on the workpiece were also studied.