Machinability investigation in electric discharge machining of carbon fiber reinforced composites for aerospace applications

The industry is looking forward to technological advancements for productivity improvement, and this can be achieved by improving the machining performance concerned with the machinability challenges. The machinability investigation of carbon nanotubes/carbon fiber (CNTs/CF) reinforced composites is emerging with a strong application potential in the aviation industry because of their high strength and lightweight nature. However, the conventional machining practices pose a major challenge of excessive tool wear and dimensional accuracy which lead to a high production cost. Electric discharge machining is considered one of the possible solutions to treat with hard to machine materials like CNT/CF. Therefore, this work involves the machinability investigation to study the effect of pulse on duration, pulse peak current, duty factor, and gap voltage to investigate the material removal mechanism for achieving machining stability along with improved dimensional accuracy. Experiments were designed using Taguchi design followed by the analysis of variance, parametric effects, along with signal to noise ratio-based multi-response optimization. Findings have inferred that peak current and gap voltage were found to be significant for radial over-cut, contributing 47.27% and 40.25%, respectively. The gap voltage was also shown to be notable for electrode wear rate and material removal rate, with contribution percentages of 43.59% and 20.11%, respectively. As a result, Vg was identified as the most influential variable in this study. This machinability study imparts a significant potential to improve the dimensional accuracy and productivity for aerospace applications.