POST-PROCESSING OF ADDITIVELY MANUFACTURED SS316 EMPLOYING DIE SINKING EDM

Selective laser melting (SLM) stands out as an additive manufacturing (AM) technique enabling the production of highly complex, fully functional metallic parts with some limitations of poor surface roughness and average mechanical properties.The SLM-produced specimens demonstrated an average surface roughness of 11.25 µm, and an average microhardness of approximately 201HV.There are numerous surface treatments reported in the literature both conventional (milling) and non-conventional (laser polishing, chemical polishing, abrasive finishing, and Surface Mechanical Attrition Treatment (SMAT)).However, these secondary surface treatments face challenges such as significantly extended processing time, effectiveness for finishing complex parts, and applicability is limited to certain materials.In this study, an unconventional technique Die-sinking electro-discharge machining (EDM) has been proposed to improve the surface quality of AM specimens.Stainless Steel SS316, a ferritic chromium-nickel stainless steel containing purposeful amounts of molybdenum, exhibits enhanced general corrosion resistance.SS316 is the preferred choice for pharmaceutical equipment, cryogenic piping, pulp and paper, and food industries.This study delves into investigating the effect of machining conditions (Ip, Ton, and Toff) on the surface integrity of SLM-printed SS316 employing die-sinking EDM.The results of experiments manifest that at higher levels of pulse current and pulse on time, the surface roughness and surface microhardness of the printed specimens are improved to 3.72μm and 341.667 HV, respectively.