Abstract
The air film holes in aero-engine turbine blades are closely arranged, with small hole diameters, and high requirements for surface quality and positional accuracy, which makes it difficult for traditional machining to meet its manufacturing accuracy requirements. To solve this problem, micro-hole machining simulation is carried out in the paper, using water-jet guided laser technology with GH4169 superalloy as the research object. First of all, the three-dimensional transient temperature field and material removal model of GH4169 superalloy was established based on the simulation software of Comsol, and the material removal mechanism of water-jet guided laser micro-hole machining was revealed. Then, comparative experiments between water-jet guided laser and traditional laser micro-hole machining were carried out with different laser powers. Finally, through the measurement of the morphology and roughness of the hole wall, it is possible to verify the feasibility of water-jet guided laser micro-hole machining and to obtain the optimal machining parameters. The experimental results show that the micro-hole surface roughness obtained by the processing is 1.362µm with a smaller heat-affected zone in the laser power of 200W, pulse frequency of 6000Hz, and water beam pressure of 2.0MPa, while the micro-hole surface roughness obtained by the traditional dry laser under the same processing parameters is 13.517µm. Therefore, water-jet guided laser processing can make a better balance of the uneven heat transfer phenomenon in the processing, and improve the processing efficiency with better surface morphology.