PCD Tool Wear Mechanism and Prediction in Laser–Ultrasonic Synergistic Milling of High-Volume-Fraction SiCp/Al Composites

To address severe PCD tool wear during the milling of high-volume-fraction SiCp/Al composites, a synergistic milling process coupling pulsed laser pretreatment with ultrasonic vibration was proposed. Five-factor, four-level orthogonal experiments were conducted on 70 vol.% SiCp/Al composites to investigate the effects of milling speed, feed per tooth, cutting depth, laser power, and ultrasonic amplitude on milling forces and tool wear, and a tool wear prediction model was established. The results showed that the factors influencing tool wear, in descending order, were feed per tooth, cutting depth, milling speed, laser power, and ultrasonic amplitude. Appropriate laser power and ultrasonic amplitude reduced cutting loads and suppressed tool wear. The model achieved a coefficient of determination of 0.7887 and was statistically significant overall. The optimal parameter combination was 50 m/min, 0.02 mm/z, 0.1 mm, 60 W, and 3.5 μm, under which the tool wear loss was 1.0 mg, representing a reduction of 61.54% compared with the maximum-wear condition. The main wear modes of the PCD tool included rake-face grooving and fatigue spalling, flank-face abrasive wear, and cutting-edge micro-chipping. These findings provide a useful reference for the precision milling of SiCp/Al composites.