Automated Fiber Placement of Thermoplastic Composites Using Fiber Laser

Abstract

A particular attention in the aerospace sector is given to manufacturing high quality thermoplastic composite parts at low cost using a true out-of-autoclave, automated placement process. In-situ consolidation of thermoplastic composites with fiber lasers permits production of good quality parts at efficient rates. A ring manufacturing setup has been developed capable of in-situ consolidation of thermoplastic composite tapes using a 2kW fiber laser. A Design of Experiment (DOE) using Taguchi method is carried out to find near-optimum condition within the processing window. Mechanical properties of rings made of 6.35 mm (¼ inch) wide carbon fiber/PEEK thermoplastic tape are investigated by examining three factors: laser power, feed rate, and pressure. Four levels are selected for each factor to provide the most information on the non-linear behavior of factors. To assure the repeatability of the process 3 samples of each ring are made at different times. Short beam shear test is performed to provide a quantitative measure of bonding quality. The results suggest that while compaction force has negligible effect on bond strength, the process is sensitive to placement rate and laser power.