Research Information System
Composites Part B: Engineering, vol.322, 2026 (SCI-Expanded, Scopus)
Developing reliable and sustainable machining strategies for CF/PEEK composites has become an urgent necessity due to the growing demand for recyclable high-performance materials in aerospace applications and the persistent lack of drilling knowledge tailored to their thermally sensitive and damage-prone nature. In this context, the focus of this study is the drilling performance of CF/PEEK thermoplastic composites. Addressing a current research gap, this study examined specific drill point angles in dry drilling CF/PEEK for the first time. The input parameters considered are the drill point angles (DPAs) of 80°, 80/120° and 120°, which have not been examined before, as well as the spindle speed (S) of 1000, 1500 and 2000 rpm and the feed rate (f) of 100, 200 and 300 mm/min. Drilling performance was evaluated regarding thrust force (Ft), cutting temperature (Tc), surface roughness (Ra), hole quality, and roundness error (RE). Using a 120° DPA and under appropriate process conditions, improvements of up to 81.1%, 57.2%, 69.2%, and 75.8% were achieved for Ft, Tc, Ra, and RE, respectively. Furthermore, the optimal drilling condition was determined through the integration of the Multi-Objective Water Cycle Algorithm (MOWCA) and the Entropy-based MARCOS multi-criteria decision-making approach. Based on the ranking results, the best process parameter combination was identified as a DPA of 120°, S of 2000 rpm, and f of 100 mm/min. Under these optimal conditions, the optimized output parameters were obtained as 306.79 N for Ft, 177.18 °C for Tc, 0.4655 μm for Ra, and 0.3264 mm for RE. These findings provide practical machining guidelines for overcoming the challenges of dry drilling CF/PEEK thermoplastic composites, thereby supporting their reliable integration into the aerospace manufacturing process.