Investigating the impact of LASER assistance on the accuracy of micro-holes generated in carbon fiber reinforced polymer composite by electrochemical discharge machining

Abstract

Electrochemical discharge machining (ECDM) is a prominent hybrid process for machining of difficult to cut materials. In recent years, various research investigations have been attempted to enhance the process capability of ECDM using further hybridization with ultrasonic, magnetic, rotary assistance etc. In present work, an attempt has been made to enhance the process capability of ECDM process by LASER assistance. The proposed technique explore the effect of LASER assisted electrochemical discharge machining (LA-ECDM) on output quality characteristics such as overcut and taper of hole. The purpose of low power LASER is assist the machining process by localized heating of electrolyte. A comparative study has been performed between LA-ECDM and ECDM process. Carbon fiber reinforced polymer composite was machined with four input process parameters as tool diameter, tool travel rate, tool rotation and duty cycle. The investigation reveals that overcut and taper of hole decreases approximately by 10–12 % with assistance of LASER. The micro-hole machined by LA-ECDM exhibits superior machining quality in terms of circularity of hole, dimensional accuracy and surface damages. SEM micrographs shows uniform distribution of carbon fibers all along the machined surface. This improvement is attributed to formation of stable and thinner gas film during machining. The behaviour of gas film and spark phenomenon during ECDM and LA-ECDM has been investigated using high shutter speed camera.