Investigation on localisation and three-dimensional micro-etching based on pulse laser electrochemical machining

By integrating indium tin oxide (ITO) conductive glass into the laser electrochemical micro machining system as tool cathode, the efficient combination of laser electrochemical machining is achieved with laser irradiation. In the established experimental system, the aluminum alloy is etched by the compound processing of laser and electrochemistry. The thermal-mechanical shock effect of laser local irradiation could remove the passivation layer in a uniform electric field, and the material at this zone is etched. However, the other regional material could not be removed because of the protection of the passivation layer, which enhances the localisation of electrochemical machining significantly. The influence mechanism of the thermal-mechanical shock of laser and the refraction characteristic of bubbles on the localization of combined machining is investigated theoretically. Based on the experiment result, the influence of the laser power, machining current and different processing methods on the localization of combined machining is also analyzed. The stray-current corrosion is restrained effectively and a three dimensional cavity with good shape precision and surface quality is acquired successfully with reasonable processing parameters. ©2014 Journal of Mechanical Engineering