Thermo-mechanical coupled analysis and experimental study on laser machining of finger seals

As a sealing technology for aero-engines, finger seals play a crucial role in improving engine thrust-to-weight ratio and reducing fuel consumption. Carbon fiber-reinforced carbon matrix (C/C) composites exhibit excellent self-lubricating and wear-resistant properties, which are well matched to the requirements and application environments of dynamic sealing technology, and can significantly extend the service life of finger seals. This study focused on the laser cutting process of C/C composite finger seals. A numerical simulation model of the laser cutting process was established using thermal-mechanical coupling simulation analysis. Through systematic simulation calculations, the influence patterns of laser processing power and feed speed on workpiece displacement and deformation were analyzed. Actual machining experiments were conducted using a continuous-fiber laser. All experiments adopted the identical laser system, where laser type, wavelength and beam quality remained constant throughout the tests. Combined with practical machining trials, core indicators including cut-surface morphology, multi-directional displacement-deformation, as well as stress-strain distributions were comprehensively investigated. The results show that processing power and feed speed are key parameters for controlling laser cutting quality. Reasonably reducing processing power can effectively suppress workpiece displacement and deformation, while increasing feed speed can narrow the thermal damage range in the cutting zone. The simulation results show good agreement with experimental measurements in terms of variation trends, verifying the rationality of the thermo-mechanical coupling model.