Electrochemical machining of 3D printed NiTi alloy: A preliminary study

Electrochemical machining represents a viable approach for enhancing the surface quality of additively manufactured Nitinol components, which typically exhibit excessive roughness. In this study, the electrochemical behavior of Nitinol was examined in chloride- and nitrate-based solutions to evaluate their effectiveness in material removal and surface refinement. Potentiodynamic polarization tests indicated that these solutions facilitate alloy dissolution, with diffusion-controlled kinetics observed at elevated potentials. Preliminary ECM experiments demonstrated that the incorporation of Na2EDTA into chloride-based solutions increased material removal, likely due to the formation of highly soluble nickel and titanium complexes. Surface analysis revealed that chloride-containing solutions promoted selective nickel dissolution, while the combined chloride-nitrate solution mitigated process selectivity and reduced surface oxidation. These findings underscore the potential of ECM as an effective post-processing technique for improving the surface characteristics of Nitinol components fabricated via additive manufacturing.