| About this Abstract |
| Meeting |
2025 TMS Annual Meeting & Exhibition
|
| Symposium
|
Additive Manufacturing: Length-Scale Phenomena in Mechanical Response
|
| Presentation Title |
Analyzing Hydrogen Diffusivity and Its Impact on Mechanical Behavior in Additively Manufactured FCC Alloys Using Nanoindentation |
| Author(s) |
Dong-Hyun Lee, Yun Hee An, Yakai Zhao, Ju Hyeok Lee, Hyun You Kim, You Sub Kim, Soo Yeol Lee |
| On-Site Speaker (Planned) |
Dong-Hyun Lee |
| Abstract Scope |
Hydrogen diffusivity significantly affects the susceptibility of metals and alloys to hydrogen embrittlement. This study introduces a novel method to estimate hydrogen diffusivity in FCC alloys using nanoindentation experiments. By considering the plastic zone size around the indentation, the relationship between hydrogen-induced hardness changes and depth from the sample surface was established for two typical FCC alloys—316L stainless steel (SS) and CoCrNi medium-entropy alloy (MEA)—subjected to hydrogen charging and subsequent room-temperature aging. Combining this with the estimation of the through-thickness hydrogen concentration distribution, hydrogen diffusivity values were successfully determined. It was revealed that CoCrNi MEA exhibited a hydrogen diffusivity approximately 0.68 times higher than SS316L. Additionally, hydrogen-induced softening upon long-term aging at room temperature was observed in CoCrNi but not in SS316L. The distinct hydrogen-related phenomena in CoCrNi MEA were elucidated using density functional theory calculations of hydrogen solution energy and vacancy formation energy. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Additive Manufacturing, Characterization, High-Entropy Alloys |