ABSTRACT
As there is rapid growth in the development of hard and difficult-to-machine materials like ceramics, stainless steel, high-speed steels, and many other alloys, unconventional machining is more significant these days. Electric discharge machining (EDM) is one of the important unconventional machining processes in which material is removed by erosion caused by repetitive sparks produced between the workpiece and tool submerged in a dielectric medium without any contact between them. Despite the advantages of EDM, we need to advance the EDM technique to further optimize the process and workpiece 206characteristics. Powder mixed electric discharge machining (PMEDM) is one of the advancements in the EDM process, which can coat simultaneously on the workpiece. In this method, the powder is added to the dielectric, which changes the properties of the gap, thereby enhancing the characteristic of the process and workpiece. Different optimization techniques like response surface methodology (RSM) Taguchi method for different input parameters were discussed in the chapter. Response variables like material removal rate (MRR), tool wear resistance, surface roughness, crater depth and width, the thickness of the white layer, and surface material accretion of the PMEDM process were discussed when different powder additives were added to the dielectric. In this EDM, different types of powders like graphite, Aluminum, Silicon carbide, chromium, and Titanium carbide are used. From various studies, it was concluded that powder addition could increase discharge current and discharge gap. When powders are used, machining becomes more stable. Studies have shown that Silicon carbide powder gives minimum MRR, and graphite powder gives maximum MRR. Powders like silicon give a good, polished surface.
