Tolerance-constrained inverse design of ceramic core configuration for precision wall thickness control in hollow turbine blades

Abstract

Wall thickness deviation significantly diminishes the durability and efficiency of turbine blades. It primarily results from surface deformation and positional shifts of the ceramic core during casting, which disrupts core-shell alignment. A novel reverse adjustment method for ceramic core positions within turbine blades based on the measurement of a batch of blades was proposed in this work. Initially, the optimal position solution model for internal ceramic cores of turbine blades on the basis of industrial computed tomography (ICT) scanning was established. Subsequently, a reverse adjustment method was developed to optimize the position and orientation of ceramic cores within the blade interior. The proposed method was verified through casting experiments, revealing a reduction of 45.5% in the maximum wall thickness error of the adjusted blades compared to their initial condition. The wall thickness error at the leading and trailing edges of the blade is reduced to less than ±0.15 mm, while the wall thickness error on the concave and convex surfaces is minimized to less than ±0.2 mm, which essentially satisfies the prescribed wall thickness tolerance requirements. The process system for precise shape control of hollow turbine blade wall thickness is further refined, providing robust technical support for enhancing the conformity rate of hollow turbine blade wall thickness dimensions.