About this Abstract |
Meeting |
2025 TMS Annual Meeting & Exhibition
|
Symposium
|
Environmentally Assisted Cracking: Theory and Practice
|
Presentation Title |
Mapping and mitigating of oxidation mechanism transitions in tungsten driven by scale cracking |
Author(s) |
Samuel A. Humphry-Baker, James Davidson |
On-Site Speaker (Planned) |
Samuel A. Humphry-Baker |
Abstract Scope |
Tungsten is a leading candidate for the first-wall and neutron shielding in a tokamak fusion power plant. In an accident scenario involving a loss of coolant, the material may be oxidised at high temperature. The density mismatch between the oxide and substrate leads to crack formation, scale spalling, dust formation and the potential release of hazardous transmutation products into the environment. In this presentation we describe a new oxidation mechanism mapping tool that allows prediction of scale fracture – and the accompanying transition from parabolic-to-linear oxidation kinetics – in time-temperature space. Tungsten-based materials with boron and silicon additions are also mapped. These materials have improved resistance to scale fracture. The B-containing materials are only effective up to 1000 °C due to the volatilisation of the boria scale. By comparison, the Si-containing form a borosilicate scale, which is stable well above 1000 °C. |
Proceedings Inclusion? |
Planned: |
Keywords |
Environmental Effects, Nuclear Materials, Ceramics |