Effect of input process parameters on MRR in micro EDM drilling of CFRP sheet using RSM

Abstract

In recent years, composite materials are replaced most conventional (industrial) materials such as steel, aluminum, copper, etc. since, CFRP material is one of the most widely used composite materials due to its excellent mechanical as well as physical properties, including strength, modulus, and compressive strength. EDM micro-holes in CFRP composites present a challenge due to fiber orientation, uneven distribution of conducting fiber, and delamination, which affect material removal rate (MRR) and micro-hole quality. This article aims to optimize input process parameters for optimum MRR. Micro EDM input parameters such as voltage, capacitance, and electrode rotation speed are examined on the MRR of micro-holes by using response surface methodology. Experiments were conducted based on the Box-Behnken design of experiment. In the experiment, capacitance was found to be the most significant factor among all input process parameters affecting MRR. Regression equations and response surfaces are developed and the results are that capacitance and rotation speed of the electrode are increased initially, and the MRR increases, however, its value decreases as the capacitance and voltage are increased further. The optimum MRR is obtained in the range of 150–250 nF capacitance, at 100 V.