Effect of Process Parameters on Machined Surface Hardness after Electrical Discharge Machining

In the machining process, it is difficult to solve problems due to the relationship between productivity and quality, for example, as the productivity increases, the quality of reprocessing may decrease. Some methods only address specific objectives, such as the quality of the machining method, the machining productivity, the quality, or even the cost. In this study, micro-hardness (HV) of the machined surface after titanium powder mixed electric discharge machining (PMEDM) is presented. The Taguchi method is applied to the processing parameters to investigate. The intent of the present study is to study the effect of different input parameters, namely, workpiece material, tool material, polarity, pulse-on time, intensity of discharge, pulse-off time, powder concentration and some their interactions on the micro hardness. Electrode material, pulse on time, powder concentration, and interactions (AG, BG) have a strong influence on HV. Powder concentration affected most strongly to HV.