Development of Laser and Electrochemical Machining Based on Internal Total Reflection

To address the issues of the existing laser and electrochemical machining (LECM) processes in controlling the machining precision, machining depth limit, and taper angle, a novel LECM based on internal total reflection (LECM-ITR) has been proposed. In LECM-ITR, both the electrolyte jet and laser beam were guided and transferred to the machining area, synchronously. Since the tube electrode could feed into the workpiece, the laser could act on the high depth machining area with less laser attenuation. The materials could be removed by using laser-materials interaction and electrochemical dissolution. Small holes with depth of 2 mm have been processed on aluminum alloy and stainless-steel workpiece successfully. Experimental results showed that LECM-ITR could decrease the side gap by 23.6%, reduce the taper angle by 60.8%, and improve materials removal rate by 118.8%. The mechanism of materials removal rate and precision enhancement by LECM-ITR were discussed, including (1) Laser induced temperature rise at the machining area could improve the machining efficiency of ECM with the increased electric current density; (2) The formed anodic oxide layer in larger thickness could enhance the machining precision of ECM with increasing time constant of the electric double layer at the machining area.