Three-dimensional simulation of micro-milling marks induced by tool-attachment errors

Surface roughness of micro-slow-wave structures in vacuum electron devices significantly affects amplification efficiency owing to skin-depth effects. To investigate the mechanism of milling-induced surface-texture formation, a three-dimensional model was established to predict micro-milling marks. The model incorporated tool-attachment errors into a radial throw amplification framework under high-speed rotation and integrated multiple influencing factors, including tool tilt angle, modal vibrations, and residual height caused by tool wear, to simulate the formation of S-shaped surface features. Simulation results revealed that the tilt angle introduced by attachment errors was the dominant factor affecting the three-dimensional morphology of milling marks, whereas modal vibrations led to asymmetrical texture distributions. Micro-milling experiments confirmed that the predicted surface topographies closely align with the measured textures, validating the reliability of the model. Experimental results indicated that increased cutting depths and feed rates intensified the tilt angle and surface roughness, whereas severe tool wear led to additional defects and asymmetric material removal not captured by simulations. In-situ measurements and attachment-error adjustments improved the bottom surface roughness of 100 μm-wide micro-grooves in alumina dispersion-strengthened copper from Ra 60–170 nm to Ra 20–70 nm. This study provides a comprehensive theoretical and experimental foundation for improving surface quality in precision micro-milling applications.