Additionally, the area roughness at 5 mm s−1 has a larger standard deviation than lower velocities. This shows that process-related plasma polishing takes some time to remove the peaks of the surfaces. This is not possible at velocities greater than 1 mm s−1. The best average area roughness of 0.093 µm was achieved at a polishing rate of 0.3 mm s−1 and a applied potential difference of 300 V.