Performance Analysis of SS312 Stainless Steel in Electrochemical Micromachining Using Copper Tool and NaCl Electrolyte

Stainless steel SS312 is widely used in chemical processing, marine, pressure vessels, and structural components owing to its high strength, corrosion resistance, and thermal stability. Its high mechanical qualities render it difficult to machine using traditional methods. The solution to the complex and burr-free features in SS312 is Microchemical Micromachining (ECMM) on a tool-free controlled anodic dissolution where there is no tool wear or thermal distortion. A tool with an electrolyte parameter interaction significantly affects the productivity, dimensional accuracy, and surface quality. This study examines the effects of voltage, duty cycle, and feed rate on the material removal rate (MRR), overcut, surface roughness (Ra), and taper angle when ECMing SS312 with a copper cathode tool and NaCl electrolyte. The Taguchi analysis indicated that the first factor influencing the MRR was the voltage, followed by the duty cycle and feed rate. The MRR increased with voltage up to 12 V, reaching a maximum of 0.0018 g/min, but reduced slightly at 14 V owing to passive layer formation. A higher duty cycle (65%) enhanced the MRR, leading to a minimum increase in overcut and Ra. By increasing the feed rate from 0.5 mm/min to 0.7 mm/min, the MRR was increased, and excessive feed caused minor dimensional deviations. The optimal setting for maximum MRR was obtained at 12 V, 65% duty cycle, and 0.7 mm/min feed, while smoother surfaces were achieved under 14 V and 55% duty cycle. Higher voltage and duty cycle help in material removal, and moderate parametric combinations are preferable for minimizing the overcut, taper, and surface roughness.