Figure 7

(a) Real-time images of by-product and gas-bubble evolution at different frames in ECM and hybrid laser-ECM process at applied voltage of 20 V (b) A zoom-in view of the image 1 in (a) showing H₂ bubble movement up along the cathode. (c) A zoom-in view of the image 2 in (a) showing generation of larger amount of H₂ bubbles and their movement up along the cathode. (d, e) Regions of interest in (c) are zoomed at two time-frames. Image in (d) gives a more clear picture of H₂ bubble movement up along the cathodic tool. Image in (d) shows bubble growth and detachment from the tool. It is clear that amount of bubble and by-product generation is more at 20 V as compared to 10 V and higher in hybrid laser-ECM as compared to ECM process at same voltage. All frames shown above are real images subjected to brightness and contrast adjustments to be able to distinguish between by-products and bubbles. The dashed red arrows indicate the direction of H₂ bubble movement.