Development of piezoactuator based rotary tool feeding system for micro-EDM

Abstract

Micro Electrical Discharge Machining (micro-EDM) is widely employed for the fabrication of component parts used in Micro Electro Mechanical System (MEMS) devices and many other applications. Spark gap, being a critical process parameter in micro-EDM, must be maintained at optimum length for stable machining. To meet this critical requirement, the tool feeding system employed in micro-EDM must be capable of feeding the tool electrode adaptively to maintain the optimum spark gap. This paper proposes to develop a Flexurally Amplified Piezoactuator based rotary tool feeding system for micro-EDM. Hysteresis behavior of the piezoactuated tool feeding system is modeled using Maxwell's hysteresis model. Model based tool feed control experiments were conducted for different feed displacements ranging from 100 μm to 600 μm and spindle rotational speeds from 400 rpm to 1800 rpm. From the experimental results it is observed that the developed rotary tool feeding system performs with an error less than 1% for larger feed displacements at higher spindle speeds. Machining experiment with tool rotation enhanced blind hole depth by 29.21% compared to machining without tool rotation. [copyright information to be updated in production process]. © 2022 Elsevier Ltd. All rights reserved.