Laser-assisted scanning electrochemical machining of Ti-6Al-4 V for localized patterning

Titanium alloys are widely used in aerospace and other industries owing to their low density, high strength, and excellent corrosion resistance, yet their machinability remains challenging. Electrochemical machining (ECM) is a promising non-contact approach; however, the formation of a stable passive film on titanium alloys often suppresses anodic dissolution in scanning ECM. In this study, we propose laser-assisted scanning ECM using an electrolyte suction tool, in which nanosecond laser irradiation locally disrupts the passive film and activates electrochemical dissolution. Parametric experiments identified conditions that produced a V-shaped groove along the laser path even when ECM alone was ineffective. The optimized parameters were an applied voltage of 9.0 V, a laser fluence of 0.5 J/cm², a scanning speed of 0.25 mm/s, and a 2.0 s irradiation followed by a 2.0 s interval. In addition, extending the voltage application time to 12.0 s after laser irradiation improved groove uniformity. High-speed observation of the electrolyte film during scanning indicated that vigorous bubble generation at higher laser fluences disturbed the current distrubusion, whereas stable machining was achieved by using a lower laser fluence and a slower scanning speed. These results demonstrate that controlling laser activation and post-irradiation voltage duration enables localized pattern machining of Ti-6Al-4 V.