In-situ investigation of the surface-topography during anodic dissolution of copper under near-ECM conditions

Electrochemical machining is characterized by deliberate high speed anodic dissolution. The distance between anode and cathode are only a few hundred microns. Additionally, the electrolyte flow rate is in the range of approximately meter/second. A special electrochemical cell design was developed to investigate the surface topography during the anodic dissolution simultaneously and in-situ under near-ECM conditions. The anode was directly placed under the cathode with a gap of 350 µm. We carried out pulse experiments at 15 A/cm2 and 25 A/cm2 with an electrolyte flow rate of 4m/s. First-time it was possible to observe the surface changing of the anode directly during current pulses by using a video camera. Different stages e.g. roughening, film formation or gas evolution could be distinguished.