Experimental Investigation on Micro-Electrical Discharge Machining process for heat treated Nickel-based Nimonic 80A

Abstract

ABSTRACT Nimonic 80 A is a nickel-based alloy having diverse applications in aerospace, automotive, biomedical, and military sectors owing to its immense strength to weight proportion and resistance to corrosion at raised temperatures. As a result of the problems associated with its conventional machining, unconventional machining, in particular, EDM is preferred. Micro-machining has become a key attraction point for manufacturing organizations. This requires to have an understanding of the process in terms of the impact of control factors on the performance characteristics. In the prevailing experimentation, micro holes were drilled on a heat-treated Nimonic 80A plate. Current, pulse-on time and pulse-off time are considered as the control factors, whereas tool wear ratio and drilling rate are considered as the performance variables. The experiments were designed using RSM. ANOVA has been carried out and the SEM analysis of the drilled hole was performed for examining the quality of the holes. The measurement of the thickness of recast layer was performed. Copper and zinc, diffused around the micro-drilled area, were identified through the elemental composition of the drilled sample using EDX. Minimum tool wear ratio and the maximum drilling rate were obtained to be 0.78 and 0.77 mm/sec, respectively.