Study on parameter’s optimization for the minimizing of the residual stress in powder mixed near-dry electric discharge machining

There are some undesired effects left in the machined products by electric discharge machining (EDM) and the most prominent among those is the residual stress. These induced residual stresses influence fatigue behavior, dimensional stability, and stress corrosion which is responsible for the failure of the machined product. It was observed that the products obtained by powder mixed near dry- EDM or (PMND-EDM) have a considerably low value of residual stress (RS). The objective of this research is to minimize the residual stresses induced in the machined workpiece (EN-31) by optimizing the process parameters which affects the machining characteristics significantly. Selected parameters were tool diameter, mist flow rate, metallic powder concentration, and mist pressure while the workpiece selected was EN-31 due to its desirable mechanical properties and immense applications in the manufacturing industry. The minimum value of residual stress at optimized values of process parameters was found to be 106.32 MPa.