About this Abstract |
| Meeting |
2027 TMS Annual Meeting & Exhibition
|
| Symposium
|
Interstitial–Metal Interactions: The Outsized Role of Small Atoms
|
| Presentation Title |
Bubble Growth from Interstitial Helium in Palladium: An Atomistic Study |
| Author(s) |
An Tien Ta, Ian S Winter, Xiaowang Zhou, Ryan B. Sills, David B. Robinson, Norman C. Bartelt |
| On-Site Speaker (Planned) |
An Tien Ta |
| Abstract Scope |
Palladium (Pd) is a promising material for hydrogen-isotope storage due to its high storage density and rapid lattice hydrogen diffusion. However, tritium radioactively decays into helium-3 (3He), an insoluble interstitial species in Pd that eventually precipitates to form bubbles and compromises Pd’s structural integrity. The atomic-scale mechanisms governing bubble growth, such as loop punching, remain unvalidated. Here we used molecular dynamics simulations to incrementally introduce He into a cavity within a Pd matrix. Our simulations revealed intricate defect structures at the growing bubble surface consisting of dislocation networks resembling a surface reconstruction phase. These networks evolved during bubble growth, suggesting that bubble expansion is mediated by these defect phases. We will discuss the observed phenomena from our simulations and the interplay between bubble pressure and defect-phase evolution driven by radiogenic interstitial 3He accumulation. SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Computational Materials Science & Engineering, Modeling and Simulation, Nuclear Materials |