Abstract: This study systematically investigates the influence of bias voltage on the microstructure and tribological performance of TiAlN coatings deposited via arc ion plating. Three distinct coating samples were synthesized under a nitrogen atmosphere by applying different substrate bias voltages: –50 V, –100 V, and –150 V. By adjusting the bias voltage, the energy of deposited ions was effectively controlled, thereby affecting the growth behavior and resulting properties of the coatings. The morphological features, elemental distribution, and chemical composition of the coatings were examined using field emission scanning electron microscopy （FE-SEM） coupled with energy dispersive spectroscopy （EDS）. The cross-sectional images revealed a typical columnar growth structure for all coatings, with a noticeable increase in densification as the bias voltage was elevated, which could be attributed to the enhanced ion bombardment effect that promoted adatom diffusion and reduced shadowing effects. X-ray diffraction （XRD） analysis indicated that all coatings maintained a single face-centered cubic （fcc） phase corresponding to （Ti, Al）N, without evidence of secondary phases, suggesting that the bias voltage within this range did not significantly alter the phase structure. Mechanical properties were assessed via nanoindentation tests, and the results showed that the hardness of the TiAlN coatings first increased and then decreased as the bias voltage rose from –50 V to –150 V. The maximum hardness of 32.1 GPa was achieved at –100 V, owing to a combination of factors including grain refinement, denser microstructure, and compressive stress introduction.Tribological properties were evaluated via ball-on-disk wear tests under dry sliding conditions. The results indicated that both the friction coefficient and the specific wear rate increased with higher bias voltages. The sample prepared at –50 V exhibited the best tribological performance, with a friction coefficient of 0.67 and a wear rate of 4.17×10⁻⁶ mm³/（N·m）. This behavior was likely due to the reduced defect density and smoother morphology at lower bias voltages, which minimized abrasive wear and delamination. The findings underscore that optimizing substrate bias voltage provides an effective method for tailoring the mechanical and tribological properties of TiAlN coatings, offering valuable insights for enhancing the surface performance of carbide tools in demanding machining applications.