About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Advanced Characterization Techniques for Quantifying and Modeling Deformation
|
| Presentation Title |
G-3: Dynamic Grain-Boundary Strengthening Contributes to Hardening During Microindentation |
| Author(s) |
Mina Dehghan, Ahmed Alade Tiamiyu |
| On-Site Speaker (Planned) |
Ahmed Alade Tiamiyu |
| Abstract Scope |
Grain-refinement by continuous-dynamic recrystallization (cDRX) is usually associated with high strain/strain-rate conditions, rather than static conditions obtainable in microindentation. However, previous works on microindentation of predeformed-metals are not site-specific; no evidence of how the microstructure evolved. Two limitations may obscure actual microstructural evolution during microindentation: constraints in characterizing large-sized indents and the problem of accessing deep regions of interest using conventional focused-ion beam (FIB) method. Using LaserFIB processes and custom-FIB lift-out grids to overcome these constraints, we demonstrate that complete grain-refinement by cDRX occurs during microindentation of a predeformed dislocation cell-ladened metal, a phenomenon we term interrupted-cDRX (icDRX): evolution of ultrafine near-equiaxed grains from dislocation cells during indentation. This results in grain-boundary strengthening contribution that leads to an unusually high hardness value for aluminum rather than the long-standing “pure” dislocation hardening. These findings represent a significant advancement as they broaden the range of indentation-hardening mechanisms that are currently understood. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Characterization, Other, Other |