| About this Abstract |
| Meeting |
MS&T24: Materials Science & Technology
|
| Symposium
|
Advanced Characterization of Materials for Nuclear, Radiation, and Extreme Environments V
|
| Presentation Title |
Investigation of Helium Bubble Formation at Tungsten-Dispersoid Interfaces in Dispersion-Strengthened Tungsten Alloys |
| Author(s) |
Ashrakat Saefan, Levko Higgins, Yongqiang Wang, Jonathan Poplawsky, Xing Wang |
| On-Site Speaker (Planned) |
Ashrakat Saefan |
| Abstract Scope |
Tungsten (W) is a promising candidate for plasma-facing materials in fusion reactors. However, it suffers from embrittlement due to recrystallization at high temperatures and ductile-to-brittle transition at low temperatures. Adding second-phase dispersoids has been shown to improve the material thermomechanical properties. Bubble formation due to high-fluence helium (He) ion irradiation is a unique challenge for plasma-facing materials in tokamak divertors. Here, we investigated the bubble formation in dispersoid-strengthened tungsten (DS-W) irradiated by 200 KeV He+ to the fluence of 4.5×1017 cm-2 at 850 °C. Transmission electron microscopy (TEM) analysis showed that the W-dispersoid interfaces generally suppress the He bubble formation, except in regions of W-dispersoid element intermixing. Both TEM and atom probe tomography analyses suggested that the intermixing may result in the formation of new phases that potentially enhance vacancy migration and bubble growth locally. The results will guide the design of DS-W with high tolerance to He ion irradiation. |