| About this Abstract |
| Meeting |
2020 TMS Annual Meeting & Exhibition
|
| Symposium
|
Advancing Current and State-of-the-Art Application of Ni- and Co-based Superalloys
|
| Presentation Title |
Evolution of Microstructure in Net-shape HIP IN718 with Improved Fatigue Performance |
| Author(s) |
Benjamin Georgin, Victor Samarov, Hamish Fraser |
| On-Site Speaker (Planned) |
Benjamin Georgin |
| Abstract Scope |
The buy-to-fly ratio of Ni-base alloys can be improved by manufacturing components via net-shape hot isostatic pressing (HIP). Historically, the fatigue performance and high temperature ductility of direct-HIP parts has been inadequate when compared with conventional processing routes. Prior particle boundary (PPB) networks form as a result of oxygen contamination of powder stock and drive fatigue performance in these materials. They serve to pin grain boundaries and provide an easy fracture path for cracks resulting in intergranular failure. Recent studies have shown that direct HIP of high purity IN718 powder stock results in a fully recrystallized microstructure with the PPB network lying within the grain interior, reducing the tendency for crack propagation. The reduced oxygen content in the powders increases the oxide interparticle separation which allows recrystallized nuclei at powder boundaries to bypass the PPB network. Homogeneous strain distributions in the powders promote uniform recrystallization and suppress abnormal grain growth. |
| Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |