Regular Article

Model characterization and mechanical property analysis of bimetallic functionally graded turbine discs

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

^* e-mail: yiweidong@xmu.edu.cn

Received: 23 September 2020
Accepted: 6 January 2021

Abstract

In advanced propulsive systems, a turbine disc bears vast mechanical and thermal loads under its working conditions of high-temperature gradients and high rotational velocity.The complex working conditions of aero-engine turbine discs place stringent performance requirements on the materials used. With dual organizations and superior composite performances, bimetallic functionally graded turbine discs have become a focus in the research of high thrust-to-weight ratio aero-engines. To study the mechanical properties of new bimetallic functionally graded materials under service conditions, we propose a volumetric fraction expression and adjustable composition distribution parameters that are suitable for simulating the composition distribution of bimetallic functionally graded turbine discs. On this basis, a characterization model for functionally graded materials based on the analysis of the internal thermodynamic properties of bimetallic turbine discs is established. The thermodynamic properties and fatigue performances of functionally graded materials under service conditions are analysed. Mechanical property simulations of functionally graded turbine discs are performed using different composition distribution parameters, and reasonable ranges are determined for the various composition distribution parameters. The results show that bimetallic functionally graded turbine discs are suitable for high-stress-gradient and high-temperature-gradient environments with lower weights than those of current GH4169 alloy turbine discs.