About this Abstract |
Meeting |
Superalloys 2024
|
Symposium
|
Superalloys 2024
|
Presentation Title |
Viscoplastic Behavior of the Grain Size Transition Zone in a Dual Microstructure Turbine Superalloy Disk |
Author(s) |
Fabio Machado Alves da Fonseca, Denis Bertheau, Loïc Signor, Julien De Jaeger, Patrick Villechaise, Jonathan Cormier |
On-Site Speaker (Planned) |
Fabio Machado Alves da Fonseca |
Abstract Scope |
This study focuses on the challenging characterization of the microstructures and the viscoplastic behavior (creep, relaxation) within the transition region of dual microstructure disks made of γ/γʹ Ni-based superalloys. This transition microstructure, consisting in spatial variations of grain sizes and/or γʹ precipitation, poses difficulties in providing insights for effective modeling strategies in aero-engines. To characterize viscoplastic behavior at intermediate temperatures, stress relaxation tests were employed using AD730TM superalloy. A single-crystalline version of AD730TM was used to isolate the effects of different precipitation states (ranging from 15 to 300 nm in size), at 700 °C and 800 °C. The results reveal a significant impact at 700 °C, while no substantial impact was observed at 800 °C. Additionally, precise specimen machining was conducted in different radial zones of a dual disk to explore the influence of various grain size gradients, on viscoplastic behavior at both 700 °C and 800 °C. The findings indicate a progressive viscoplastic behavior along the gradient of grain size for both testing temperatures. Finally, the viscoplastic behavior of transition specimens was analyzed within the framework of a grain-sensitive phenomenological model. The study provides valuable insights into understanding and modeling the complex behavior of dual microstructure disks in aero-engine applications. |
Proceedings Inclusion? |
Definite: At-meeting proceedings |