Effect of Primary Cutting Edge Geometry on the End Milling of EN AW-7075 Aluminum Alloy

This study investigates vibration signals generated during end milling of thin-walled EN AW-7075 aluminum alloy components using a set of 24 tools with distinct cut-ting-edge microgeometries. Five characteristic parameters describing the dynamic re-sponse of the process, including both energy-related and statistical indicators, were ex-tracted and analyzed. The results clearly demonstrate the critical influence of tool micro-geometry on process dynamics. In particular, the introduction of an additional ze-ro-clearance flank land at the cutting edge proved decisive in suppressing vibrations. For the most favorable geometries, the root mean square (RMS) value of vibration was reduced by more than 50%, while the spectral power density (PSD) decreased by up to 70–75% compared with the least favorable configurations. Simultaneously, both time- and fre-quency-domain responses exhibited complex and irregular patterns, highlighting the lim-itations of intuitive interpretation and the need for multi-parameter evaluation. To enable a synthetic comparison of tools, the Vibration Severity Index (VSI), which integrates RMS and kurtosis into a single composite metric, was introduced. VSI-based ranking allowed the clear identification of the most dynamically stable geometry. For the selected tool, ad-ditional analysis was conducted to evaluate the influence of cutting parameters, namely feed per tooth and radial depth of cut. The results showed that the most favorable dynam-ic behavior was achieved at a feed of 0.08 mm/tooth and a radial depth of cut of 1.0 mm, whereas boundary conditions resulted in higher kurtosis and a more impulsive signal structure. Overall, the findings confirm that properly engineered cutting-edge microgeom-etry, especially the formation of additional zero-clearance flank land significantly en-hances the dynamic of thin-wall milling, demonstrating its potential as an effective strat-egy for vibration suppression and process optimization in precision machining of light-weight structural materials.