Reducing micro-sparks using reusable and low-cost pencil graphite cathode in electrochemical micromachining of SS304

In electrochemical micromachining process (ECMM), cathodes are the microfeature creators yet, the deposition of sludge particles on the cathode surface is expected in ECMM while machining with neutral electrolytes which have a negative influence on the generated micro profile. In this research, the feasibility of reducing insoluble reactant products/sludges adhering onto the cathodic surface of the Pencil Graphite Electrode (PGE) of two variants namely the non-treated PGE (NPGE) and the LN 2 -treated PGE (CPGE) aided by the NaNO 3 electrolyte and their influence on producing burr-free micro-holes with better surface roughness (R a ) on SS304 are investigated. The XRD report confirms the presence of graphite in both the PGEs and the spectral peaks from the EDS data of the adhered sludge particles on the cathode surface reported in traces of the element Fe and O that possibly forms iron oxides (Fe 2 O 3 ) on the pencil graphite cathodes. Further, findings from the SEM images and the Brunauer–Emmett–Teller models shows the lucid results of CPGE exhibiting reduced pore-size and pore volume of 8.12 nm and 0.23 cm 3 /g, respectively that resulted in less sludge/reactant product adherence on the cathodic surface up to 75% owing to better surface finish with no burrs and no micro sparks effect.