Project Title: High temperature loss of strength in ferritic/martensitic steels for fusion energy applications
Supervisors: Prof. Adrian P. Sutton FRS, Dr. Sergei L. Dudarev
The steep loss of ultimate tensile strength (UTS) at high temperatures in ferritic/martensitic (FM) steels is a pressing issue for fusion energy applications and, in general, in the field of metallurgy. The phenomenon has been suggested to be linked to thermally-activated dislocation climb over nanometric precipitates. However, this hypothesis has not been rigorously tested yet. Dislocation dynamics (DD) simulations usually employ descriptions of dislocation climb based on mobility laws that disregard non-local effects due to the vacancy distribution, which are likely to be important when investigating interactions with precipitates. Our research aims to develop an accurate non-local model of dislocation climb, and to apply it to the study of dislocations interacting with nanometric precipitates. This modelling framework will also be employed to address other pressing questions in the field of fusion materials, such as the coarsening timescales of interstitial/vacancy prismatic loops and voids in a metal after irradiation.