A novel model reconstruction strategy for polishing turbine blade based on position optimization of sectional curve

Nowadays, the combination of hot casting and numerical control polishing is an effective and appreciated process to manufacture aero-engine turbine blades. However, casting is a hot forming process, and turbine blade will engender some geometric deviations compared to the design model, which results in a critical problem in subsequent numerical control polishing process. To solve this problem and reduce the rejection rate of blade blank, this manuscript attempts to present a novel process model reconstruction strategy in adaptive polishing of turbine blade. Firstly, the design model was sliced into several 2D sectional curves based on design manner, and these designed 2D sectional curves were measured separately using on-machine measurement (OMM) system. And then, the iterative closest point (ICP) was used to find the best position between the design model and the on-machine measurement points. Afterwards, appropriate geometrical tolerances of each 2D sectional curve were added into a constrained optimization model, which was established for finding the optimized sectional curve. Finally, the final process model was reconstructed by lofting these optimized sectional curves, which can be used for adaptive polishing. A typical turbine blade has been successfully performed to demonstrate the effectiveness and superiority of the proposed model reconstruction strategy.