Sub-pixel high precision dimensional measurement method for aero-engine hollow turbine blade based on industrial computed tomography image

作者：Yanan Wang, Sansan Shuai, Xing-fu Ren, Tong-tong Hu, Jiang Wang, Zhongming Ren · 发表于：China Foundry · 年份：2022 · DOI：10.1007/s41230-022-2044-8 · 被引用次数：13 · 研究领域：Advanced X-ray and CT Imaging、Welding Techniques and Residual Stresses、Advanced X-ray Imaging Techniques

Aero-engine hollow turbine blades are work under prolonged high temperature, requiring high dimensional accuracy. Blade profile and wall thickness are important parameters to ensure the comprehensive performance of blades, which need to be measured accurately during manufacturing process. In this study, a high accuracy industrial computed tomography (ICT) measuring method was developed based on standard cylindrical pin and ring workpieces of different sizes. Combining ICT with cubic spline interpolation, a sub-pixel accuracy was achieved in measuring the dimension of component. Compared with the traditional and whole-pixel level image measurement method, the cubic spline interpolation algorithm has the advantages of high accuracy in image edge detection and thus high accuracy of dimensional measurement. Further, the technique was employed to measure the profile and wall thickness of a typical aerospace engine turbine blade, and an accuracy higher than 0.015 mm was obtained.