Pulse parameter characterization in microdrilling of maraging steel 300 alloy

Abstract

MicroEDM process is mainly used for producing miniaturized features like microholes on different types of materials that are hard to cut and difficult to machine. One typical application of microEDM process is microhole drilling operation. Choice and utilization of optimum pulse parameters is of utmost importance for achieving superior surface quality and higher machining rates. However, the process is characterized by low machining rates and considerable overcut as compared to conventional EDM drilling. An attempt is made to investigate the effect of pulse parameters on maraging steel 300 alloy during microEDM drilling. Parameters like pulse on time, pulse off time, voltage and current are explored through 09 experiments replicated thrice using Taguchi method. Machining characteristics like material removal rate and overcut are studied while drilling micro holes of 500, µm diameter using brass electrode. Evaluation of microhardness after microdrilling is also performed. It is found that pulse on time and current influenced the machining characteristics. Minimal change is observed in the microhardness of the alloy after microdrilling.