Concept development for fabricating threaded micro-pin using wire-EDM

Abstract

Nowadays miniaturization with precision is an important requirement in the field of medical devices and high-end applications. This work introduces the concept of 3D complex geometry fabrication in microscale using typical 2-Axis wire-cut electric discharge machine (WEDM). In this regard, the threaded profile micro-pin has been chosen in the present study. Synchronizing the workpiece rotating speed with feed rate along with a suitable depth of cut is the required condition for fabricating a screw. A separate attachment has been developed and used to rotate the workpiece at different speeds. Further, a CNC code has been generated to design the tool path with the required tool feed and depth of cut. Initially, turning operation has been performed which results in reduction in the tool diameter into the desired dimension along with the elimination of the eccentricity of the rotating rod. Consequently, the thread cutting operation has been accomplished with the adjusted set of parameters. Besides, the surface topography and material characteristics of the fabricated screw fin have also been observed based on scanning electron microscopic images and energy-dispersive X-ray analysis. Finally, the established process has been escalated further to fabricate screws of minimum possible dimension using the WEDM.