A Path Planning Method for Polishing Thermal Barrier Coatings on the Surface of Aero-Engine Blades Based on Point Cloud Slicing.

Thermal barrier coatings (TBCs) can significantly improve the turbine blades' high-temperature tolerance in turbine engines, the high surface roughness for the as-sprayed coating can have an adverse effect on engine performance. In order to reduce the roughness of the blade surface coating, for aero-engines and gas turbines blades, the industry's traditional method uses abrasive belts to polish the coating by manual pickup or robot clamping. The aero-engine blade studied in this paper, itself small size, the surface exhibits significant variations in curvature, the use of abrasive belt polishing method, difficult to control the polishing effect. For the current use of the model surface-based grid point division method, due to casting errors, the generated polishing path, and the actual blade, there is part of the accuracy error. To solve these problems, this paper proposes a polishing path planning method for surface TBCs applied to small blades of aero-engine turbines. By pre-processing and point cloud slicing the 3D point cloud of the blades, a polishing path is created using point cloud discretization and the B-spline curve fitting approach, guaranteeing that the accuracy error is within 0.1 mm. Simulation and experimental verification show that the method can reduce the surface roughness of blade coating to below Ra0.7 μm, which can meet the requirements and accuracy of polishing processing, while ensuring the effective thickness of the coating. [ABSTRACT FROM AUTHOR]