Adaptive toolpath deposition method for laser net shape manufacturing and repair of turbine compressor airfoils

The aim of this research is to develop a geometry-based adaptive toolpath laser powder deposition method for the manufacturing and repair of advanced turbine engine compressor or blisk airfoils. To realize that, the design of experiments (DoE) method was used to study the deposition geometric responses of a single-pass multilayer Inconel 718 laser powder deposition process. In the first step, the processing feasibility domain was quickly explored with a set of screening DoE. The dominating factors, which have significant effects on the deposition bead width and maximum stable layer height, were identified among the various deposition parameters. Based on this result, a more accurate quadratic regression transfer function was developed to predict the deposition bead width as a function of the dominating processing parameters identified in the first step. With the transfer function, deposition toolpath for net shape airfoil fabrication or repair was designed with predetermined bead width, stable layer height, and bead overlap ratios. Adaptive deposition bead widths were obtained by varying the laser power according to the transfer function, so that a constant bead width overlap ratio was maintained. Finally, compressor and blisk airfoils repaired by the geometry-based adaptive toolpath deposition method are demonstrated.