| 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 |
Competitive Mechanisms of Fatigue Crack Initiation Around Non-metallic Inclusions of a Polycrystalline Ni-base Superalloy |
| Author(s) |
Alexander Bergsmo, Fionn Dunne |
| On-Site Speaker (Planned) |
Alexander Bergsmo |
| Abstract Scope |
Non-metallic inclusions in polycrystalline Ni-base superalloys can develop accumulated damage that results in fatigue crack initiation during fatigue loading by either particle fracture, interfacial decohesion or slip-driven initiations in the metal matrix. In this work, we investigate the micromechanical drivers of cracking and decohesion in a Ni-base superalloy, RR1000. A representative crystal plasticity finite element model, which incorporates traction-separation behaviours of interfaces has been developed in conjunction with an experiment. The development of stress within the model suggest that cracking and decohesion are stress driven and thus are dependent on the degree of strain hardening behaviour in the matrix. Predictions are made for nucleation of slip-driven cracks within the matrix using a stored energy criterion. The cycles to nucleation are then mapped on a maximum applied remote stress for the various modes of initiation and show particle fracture and decohesion occur at elevated stresses within the very first few cycles. |
| Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |