In the creation of artificial joints, such as knee and hip joints and oral prostheses, metallic biomaterials have been of great significance in recent days. Duplex stainless steel (DSS-2205) is one such material often employed for biomedical applications. The influence of silicon dioxide (SiO2) nanoparticles on the deionized water dielectric in the process of Electrical Discharge Machining (EDM) of duplex stainless steel is investigated in this study. SiO2 assists in eliminating certain pollutants present in the air. The modeling and optimization of the process parameters of SiO2 Nanopowder Mixed Electrical Discharge Machining are carried out using the Response Surface Methodology (RSM). The discharge current, voltage, spark on time, spark off time, and SiO2 levels are considered input factors once the parameters have been analyzed. The results reveal that electrical discharge machining with the synthesis of nanoparticles on the deionized water dielectric produces the best surface morphology. Furthermore, the surface topography and compositional analyses of the machined substrates were examined using field emission scanning electron microscopy and an X-ray diffractometer. The substrate surface alteration was found to be beneficial in increasing the corrosion resistance of duplex stainless steel by 96% (corrosion rate: 0.00763 mm/year) when compared to their respective untreated samples.