Construction method of process model for correcting local profile errors of turbine blades.

Turbine blades, mainly formed by investment casting, are one of the core components of an aero-engine. However, the profile accuracy of turbine blades shaped by investment casting sometimes cannot directly meet the design requirements, and there will be some local areas exceeding the given form tolerance. In order to reduce the blade rejection rate and develop an advanced CNC correcting method, a new process model construction method for CNC correction of turbine blades is proposed. In this method, a new multi-constraint optimization model for the design sectional curve position of turbine blades is developed, which not only enables the process model constructed from the optimized sectional curves to best fit the actual blade geometry but also minimizes the local error areas to be corrected on the actual geometry. Two typical turbine blades have been successfully performed to demonstrate the effectiveness of the proposed method. The results show that the proposed method can significantly reduce the local error areas compared to the existing method while not exceeding the given multiple constraints. Therefore, the constructed process model can be used to generate CNC tool paths to correct the minimum local error areas and thus convert the scrap turbine blades into qualified ones. [ABSTRACT FROM AUTHOR]