Atmospheric dual laser deposited dielectric coating on electrodes for electrochemical micromachining

•We develop a dual-laser assisted depostion method in the atmospheric environment.•A 5-μm thick TiO2/TiN film successfully protects WC electrodes used in μECM.•The machining results show the overcut can be reduced by 60% with the dielectric coating, and the depth can be increased by 15%.

Electrochemical machining (ECM) is a non-conventional manufacturing technology widely used in various industries. Recent developments in the fields of micro- and nanotechnology have precipitated the evolution of ECM to electrochemical micromachining (μECM). In μECM, the stray current between the electrode and the workpiece would severely degrade the accuracy. A dielectric coating on the electrode is the simplest effective way to reduce the stray current. Pulsed laser deposition provides an efficient coating method for a wide range of materials. In this paper, we proposed a dual laser-assisted deposition method in the atmospheric environment for dielectric TiO2/TiN film deposition on WC electrodes. The deposition process is in an ambient condition, and no vacuum is needed. With an assisting 2nd laser, the dielectric film had better adhesion to the electrode. With the 5-μm thick film, the electrode is well protected and is not consumed in the ECM process. The machining results showed that the overcut can be reduced by 60% with the dielectric coating, and the depth can be increased by 15%.