About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Mechanical Behavior at the Nanoscale VIII
|
| Presentation Title |
Unveiling Negative Creep in High-Entropy Alloys: A Spherical Nanoindentation Study of Time- and Temperature-Dependent Deformation Mechanisms |
| Author(s) |
Shreya Mukherjee, Rajiv Mishra |
| On-Site Speaker (Planned) |
Shreya Mukherjee |
| Abstract Scope |
Understanding creep behavior at high temperatures is crucial for the deployment of high-entropy alloys (HEAs) for structural applications. This study presents the first-ever systematic investigation of time- and temperature-dependent nanoindentation creep in a transformative FeMnCoCrSiCu HEA using a spherical indenter, chosen specifically to provide constant contact geometry that enables extraction of creep parameters, i.e., stress exponent and activation volume. Varying load-controlled indentation creep tests were conducted at 30 °C, 200 °C, and 500 °C, with dwell times of 100 and 500 seconds. A unique feature of the FeMnCoCrSiCu HEA is deformation induced transformation. Pronounced creep was observed even at 200 °C, with stress exponents suggesting dislocation based creep mechanism. At elevated temperatures, a distinct negative creep (plastic strain recovery during dwell) emerged, indicating a transition to different recovery mechanisms. Post-mortem site-specific EBSD and TEM was used to establish the substructural evolution, dislocation annihilation, extent of transformation and grain-level slip transfer. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
High-Entropy Alloys, Mechanical Properties, Nanotechnology |