| About this Abstract |
| Meeting |
2025 TMS Annual Meeting & Exhibition
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| Symposium
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Mechanical Response of Materials Investigated Through Novel In-Situ Experiments and Modeling
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| Presentation Title |
Influence of Unimodal and Bimodal γ' Precipitate Size Distributions on the Deformation Mechanisms in ATI 718Plus |
| Author(s) |
Geeta Kumari, M. Sundararaman, Carl J. Boehlert, Chanchal Ghosh, Mythili R, Arup Dasgupta, Jonathan Poplawsky, S. Sankaran |
| On-Site Speaker (Planned) |
Geeta Kumari |
| Abstract Scope |
This study combined novel modeling and careful transmission electron microscopy (TEM) characterization to understand how γ' precipitate size distribution affects deformation mechanisms for ATI 718Plus. 720 ℃ to 900 ℃ aging was applied to solution-treated samples, resulting in unimodal and bimodal γ' size distributions. The microstructures were tensile tested to failure to assess their yield strength, ultimate tensile strength, and elongation-to-failure. Some samples underwent interrupted tensile tests at 3-4% plastic strain, and TEM was used to study the γ' precipitate-dislocation interactions. For the unimodal samples with ~7 nm diameter γ' precipitates, dislocations sheared through the precipitates. Samples with ~24 nm diameter γ' precipitates exhibited dislocation loops and paired dislocations. The bimodal distribution, with ~6 nm and ~28 nm diameter γ' precipitates, showed shearing as the dominant deformation mechanism and exhibited the highest strength. The findings aligned with theoretical calculations of critical resolved shear stress for shearing and looping. |
| Proceedings Inclusion? |
Planned: |