Parametric investigation of laser incidence geometry in laser-assisted milling of Inconel 718

While laser-assisted milling machining is promising for promoting the machinability of Inconel 718, the geometrical parameters of laser beam relative to milling tool significantly influence its machining performance. In this work, we investigate the effects of various parameters of laser incidence geometry on the laser-assisted milling process of Inconel 718 by comprehensively employing analytical investigations, finite element simulations and experiments. Firstly, a laser-assisted milling experimental platform is constructed, and a fully coupled thermal-mechanical 3D finite element model of laser-assisted milling of Inconel 718 is established. Secondly, experiments and finite element simulations of laser-assisted milling of Inconel 718 are conducted to investigate the impact of laser assistance on cutting force and machined surface morphology. Results indicate that laser-assisted milling can moderately reduce cutting force and enhance surface quality compared to conventional milling. Thirdly, a single-factor experiment is carried out to explore the impact of laser incidence geometry parameters (laser power, laser incidence angle, and laser spot-tool edge distance) on the cutting force in laser-assisted milling of Inconel 718. Furthermore, the parametric investigation based on the response surface methodology is carried out to assess the coupled effects of the three parameters for deriving their optimal values. The experimental results show that the optimized parameters of laser-assisted milling can lead to a 47.4% reduction in surface roughness and a 25% reduction in cutting force, accompanied by significantly reduced tool wear, as compared to conventional milling. The findings demonstrate that the rational selection of laser incidence geometrical parameters is crucial for enhancing the laser-assisted milling capability for Inconel 718.