About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Mechanical Behavior at the Nanoscale VIII
|
| Presentation Title |
Studying the Evolutionary Mechanisms of Void Nucleation at Grain Boundary Regions in the Ductile Failure of Polycrystalline Tantalum Using Spherical Nanoindentation |
| Author(s) |
Olajesu Favor Olanrewaju, Kevin Jacob, Curt Bronkhorst, Nan Chen, Marko Knezevic, Sid Pathak |
| On-Site Speaker (Planned) |
Olajesu Favor Olanrewaju |
| Abstract Scope |
Our NSF-DMREF project studies the evolution of void nucleation at grain boundary regions to predict ductile failure in polycrystalline materials. Our approach employs spherical nanoindentation stress–strain techniques to characterize the local mechanical behavior of individual grains and grain boundary regions in polycrystalline tantalum, our model BCC refractory metal. Our analysis focuses on the influence of grain misorientation, elastic–plastic response, and Taylor factor mismatch. We demonstrate the capabilities of our data analysis to characterize the local indentation yield strengths and correlate them with increased slip resistance and stored energy variations (Taylor factor mismatch) across different boundaries under increasing levels of cold work (interrupted tensile experiments). Notably, hardened boundary layers grow as a function of Taylor factor mismatch, causing grain fragmentation and suppressing intragranular plasticity, increasing the likelihood of void nucleation. Our systematic approach highlights the role of different boundaries in the deformation of a multi-phase polycrystalline sample. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Characterization, High-Temperature Materials, Other |