Experimental investigations on the microhole machining of 304 stainless steel by micro-EDM process using RC-type pulse generator

摘要

In this research, microhole drilling of stainless steel grade 304 using micro-electrodischarge machining (micro-EDM) drilling has been studied. The machinability has been evaluated by means of material removal rate (MRR), tool wear rate (TWR), and accuracy of the machined microholes. During the micro-EDM drilling process, the thermal properties of the work materials were found to have a significant influence on the quality and accuracy of the microholes. Moreover, the performance parameters were also found to be influenced greatly by the thermal properties of the materials like thermal conductivity, melting point, thermal expansion coefficient, and behavior of the material at high temperature. From the observation of SEM micrographs, it is found that at a lower range of current and pulse-on time, the topographical condition of the microholes is better, and as the current and pulse-on time are increased, the microhole condition gets deteriorated.