Research on milling performance of CF/PEEK composites assisted by laser-ultrasonic vibration

Carbon fiber/polyether ether ketone (CF/PEEK) composites, known for high thermal stability (Tg = 143°C) and a wide processing window (330–380°C), are promising for aerospace and high-performance uses. Their inherent anisotropy and inhomogeneity complicate machining. A laser–ultrasound-assisted milling (LAM-UAM) method, combining laser ablation with ultrasonic pulses, is introduced to improve CF/PEEK machinability. Milling tests were performed at four fiber orientations (0°, 45°, 90°, 135°) using four strategies: conventional (CM), laser-assisted (LAM), ultrasound-assisted (UAM), and LAM-UAM. The LAM-UAM method significantly improves machining quality at all orientations. Milling forces, cutting energy, and temperature increased with fiber orientation, peaking at 90°, while surface roughness and damage showed similar trends. The LAM-UAM process reduced milling forces by 54.6%, energy by 55.7%, and temperature by 26.1% compared to CM. It also improved surface quality, with the best results at 0° orientation, with 45° and 135° orientations showing intermediate performance. The LAM-UAM method suppressed machining-induced damage, particularly at 90° fiber orientation, where damage was most pronounced. These findings provide insight into CF/PEEK machining under various orientations and offer practical guidance for efficient, low-damage processing.