About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
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Symposium
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Deformation Mechanisms, Microstructure Evolution, and Mechanical Properties of Nanoscale Materials
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Presentation Title |
Submicron Intermetallic Particle Heterogeneity Controls Shear Localization in High-strength Nanostructured Al Alloys |
Author(s) |
Tianjiao Lei, Esther C. Hessong, Jungho Shin, Daniel S. Gianola, Timothy J. Rupert |
On-Site Speaker (Planned) |
Tianjiao Lei |
Abstract Scope |
The mechanical behavior of nanocrystalline Al alloys, Al-Mg-Y and Al-Fe-Y, was investigated with in-situ micropillar compression testing. Both systems exhibited yield strengths higher than 600 MPa, due to grain boundary segregation, amorphous complexions, nanorod precipitates, and intermetallic particles. However, some micropillars plastically softened through shear banding. Post-mortem transmission electron microscopy investigation revealed that intermetallic-free deformation pathways were responsible for this failure. Further characterization showed significant grain growth and the same grain orientation within the shear band, pointing to grain boundary mechanisms for plastic flow, specifically grain rotation and/or grain boundary migration. The presence of intermetallic particles made it difficult for both matrix and intermetallic grains to rotate into the same orientation, due to the different lattice parameters and slip systems. Therefore, we conclude that a uniform distribution of intermetallics with an average spacing less than the percolation length of shear localization can effectively prevent the maturation of shear bands. |
Proceedings Inclusion? |
Planned: |
Keywords |
Aluminum, Other, |