Modeling and process optimization of water jet guided laser micro hole drilling on nickel-based aerospace alloys

Subaşı, Levent
Special aerospace alloys are used for the manufacturing of turbine blades in gas turbines and micro cooling holes are drilled on them to increase their thermal resistance. Water Jet Guided Laser (WJGL) is a novel technology that can be used to drill these holes. WJGL process overcomes the adverse effects of conventional laser drilling, but the physics of this process is very complex. Determining the proper machining parameters to achieve acceptable process time and quality is worth to be studied. In this study, the material removal mechanism of this process has been investigated, and process time and quality optimization studies have been realized. A simplified and holistic model has been developed based on statistical analysis, machine learning, and experimental studies for drilling nickel-based aerospace alloys, such as Inconel 625, Inconel 718, and CMSX-4. Additionally, real-time process monitoring solutions have been obtained. For these purposes, image processing by using a mono camera and acoustic sensing by using an optical microphone have been realized in order to measure the effective cutting length, the laser power in water, and machining conditions. The effects of hole geometries on machining efficiency have been studied and some recommendations are proposed as well.


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Citation Formats
L. Subaşı, “Modeling and process optimization of water jet guided laser micro hole drilling on nickel-based aerospace alloys,” Ph.D. - Doctoral Program, Middle East Technical University, 2022.