Modeling of shrinkage characteristics during investment casting for typical structures of hollow turbine blades
- PDF / 3,009,105 Bytes
- 12 Pages / 595.224 x 790.955 pts Page_size
- 117 Downloads / 215 Views
ORIGINAL ARTICLE
Modeling of shrinkage characteristics during investment casting for typical structures of hollow turbine blades Yiwei Dong1,2 · Weiguo Yan1 · Zongpu Wu1 · Saitao Zhang1 · Tao Liao1 · Yancheng You1 Received: 9 December 2019 / Accepted: 31 July 2020 © Springer-Verlag London Ltd., part of Springer Nature 2020
Abstract To study the coupling mechanism of shrinkage distribution and complex structures in the precision casting process of hollow turbine blades, the blade structure was simplified to a hollow thin-walled structure with resistance and nonresistance. Four different structures of casting and a casting system were designed. Based on the combination of numerical simulation and experimental measurement, the shrinkage distribution and shrinkage model of castings were established. The results show that the simulated and measured shrinkages have the same trend. Then, the structural parameters affecting shrinkage, including wall thickness, outer diameter, and unobstructed structure, were discussed. A mapping model based on a backpropagation (BP) neural network reflecting the relationship between structural parameters and shrinkage rate was constructed. According to the BP neural-network-based mapping model, the average deviations between the predicted and measured values of the transitional and normal sections are 5.8% and 2.4%, respectively, which improves the accuracy compared with existing research, indicating that the shrinkage model has a good performance in predicting shrinkage of the typical structure in hollow thin-walled castings. Keywords Hollow turbine blade · Precision casting · Shrinkage · Structural parameters · BP neural network
1 Introduction To meet the requirements of their complex working conditions and service performance, nickel-based turbine blades used in jet-engine are investment cast, mostly in a single-crystal form [1]. High-performance precise solidification and forming technology is widely used to improve temperature and load-carrying capacity. High precision of the solidification forming process can meet the requirements of casting shapes of multiple degrees of freedom, with high precision, but the process is a geometric Yiwei Dong
[email protected] 1
School of Aerospace Engineering, Xiamen University, 422 South Siming Road, Xiamen, 361005, People’s Republic of China
2
Shenzhen Research Institute, Xiamen University, No.19, Gaoxin South 4th Road, Nanshan District, Shenzhen, 518057, People’s Republic of China
one. The material and boundary conditions of triple highly nonlinear coupling complex physical processes, and the parameters, e.g., material, geometry, process, and their effect on coupling, are extremely sensitive, which makes guaranteeing the high-performance precision forming of hollow turbine blades a technical challenge. At present, the qualification rate of the single-crystal turbine blades independently manufactured in China is less than 40%, among which the unqualified rate of the blades due to size deviation accounts for 50% [2]. Owing to the inhere
Data Loading...
