About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
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Symposium
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Nanostructured Materials in Extreme Environments
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Presentation Title |
Understanding the Superior Strength and Localized Plasticity in Nanotwinned Ni-Mo-W Alloys |
Author(s) |
Mo Rigen He, Arunima Banerjee, Kevin J. Hemker |
On-Site Speaker (Planned) |
Kevin J. Hemker |
Abstract Scope |
The focus on nanoscience has greatly advanced our ability to synthesize, characterize, and model nanomaterials with unprecedented physical and chemical properties that are derived from dimensional constraints. Nanotwinned Ni-Mo-W possess ultrahigh strengths exceeding 4 GPa, which stem from its unique microstructure, ultrafine nanotwins densely packed in textured columnar grains. These materials also manifest extreme strain localization upon plastic deformation, but the microscopic mechanisms that lead to the activation and evolution of shear bands remain to be clarified. In this study, two materials with atomic composition of Ni84Mo11W5 and Ni86Mo3W11 are tested with nanoindentation and in situ SEM and TEM pillar compression. Combined with postmortem TEM imaging and orientation mapping, it is revealed that detwinning, spatially adjacent to and temporally prior to the developed shear bands, triggers the formation of shear bands. The potential role of alloy composition in facilitating early-stage plasticity and mitigating strain localization is further studied. |
Proceedings Inclusion? |
Planned: |
Keywords |
Nanotechnology, Mechanical Properties, |