Milling performance of CF/PEEK composites under pulsed laser-ultrasonic vibration coupling

Carbon fiber-reinforced polyetheretherketone (CF/PEEK) is widely used in aerospace and transportation sectors due to its low weight, high strength, and recyclability. Its hybrid brittle–ductile nature creates substantial machining challenges. This study proposes a coupled laser-assisted and ultrasonic vibration milling process to enhance the machining quality of CF/PEEK composites. Finite element modelling has investigated the damage mechanism of carbon fiber-reinforced polyether ether ketone composites under laser-assisted ultrasonic machining combined with ultrasonic machining (LAM-UAM) conditions. A one-factor milling experiment is conducted on CF/PEEK unidirectional laminates at four fiber orientations (0°, 45°, 90°, and 135°), with ultrasonic machining (UAM), laminar machining (LAM), and conventional machining (CM) serving as control groups. The variations in milling force, surface roughness, and surface damage across different machining methods and fiber orientations were analyzed. Additionally, the material removal mechanisms were examined through experimental and simulation verification. Compared with conventional machining, the LAM–UAM process reduced cutting force and surface roughness by 56.9% and 27.7% at 0° fiber orientation and 6000 r/min. Despite brittle fracture, the LAM–UAM process suppressed fiber wear and minimized surface defects, consistent with simulation results. These results offer theoretical and practical guidance for efficient, low-damage machining of CF/PEEK composites.