About this Abstract |
Meeting |
2020 TMS Annual Meeting & Exhibition
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Symposium
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Fatigue in Materials: Fundamentals, Multiscale Characterizations and Computational Modeling
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Presentation Title |
Exploring the Fundamental Role of Dislocation-twin Boundary Interactions in Fatigue |
Author(s) |
Orcun Koray Celebi, Ahmed Sameer Khan Mohammed, Francisco Andrade Chavez, Jessica Anne Krogstad, Huseyin Sehitoglu |
On-Site Speaker (Planned) |
Orcun Koray Celebi |
Abstract Scope |
Modeling microstructural dependence of fatigue crack growth behavior is vital in explaining variability in life predictions. In this regard, Twin Boundaries (TBs) play a decisive role in dictating fatigue resistance, particularly in the near threshold crack growth regime. Their influence is dependent on the nature of interaction between crack-tip emitted dislocations and the TB. However, this interaction is complex and can admit one of several possibilities depending on parameters such as the Schmid Factor of the twin interface and applied stress state. A model is proposed to explain these dependencies outlining the interplay of elastic and atomistic energy barriers in the process, particularly the core disregistry interactions when the dislocation approaches the twin. This is done through a combination of ab-initio DFT simulations and analytical tools of anisotropic elasticity. The critical influence of the TB is further evidenced through experimental characterization of crack growth behavior in carefully prepared twinned microstructures. |
Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |