Cemented carbide tools are widely used under demanding machining conditions such as deep-hole boring, where cutting-edge stability is essential for suppressing micro-chipping and maintaining machining quality. To improve edge stability, a three-factor three-level orthogonal experiment is constructed to investigate the effects of polishing disk rotational speed, slurry flow rate, and B-axis swing speed on the chemical mechanical polishing and passivation of cemented carbide tool edges. After passivation, the blunt radius increased by 20.50-42.00 μm for straight edges and 25.16-50.41 μm for arc edges, reaching 35.86-57.48 μm and 42.14-67.53 μm, respectively, with a stronger passivation response observed for arc edges. Increasing the polishing disk speed from 30 rpm to 90 rpm increased the average edge radius from 40.92 μm to 59.65 μm, with the response at 90 rpm being 1.46 times that at the 30-rpm baseline. The slurry flow rate had a weak effect, while increasing the B-axis swing speed enhanced passivation. A comprehensive multi-criteria evaluation integrating material removal, passivation stability, and forming consistency yielded sensitivity scores of 0.894, 0.616, and 0.318 for polishing disk speed, B-axis swing speed, and slurry flow rate, respectively. These results indicate that a polishing disk speed of 60-90 rpm, a slurry flow rate of 7 mL/min, and a B-axis swing speed of 3.6-4.8°/s provide a balanced process window for the chemical mechanical polishing passivation of cemented carbide tool edges.
