Ph.D. topics

Radiation tolerance of high entropy alloys

Ph. D. student

Jyoti Verma

Supervisor

Prof. Jürgen Fassbender, Gregor Hlawacek, Cornelia Kaden, Maciej Oskar Liedke (HZDR)

Department

• Ion Induced Nanostructures (Institute of Ion Beam Physics and Materials Research)
• Structural Materials (Institute of Resource Ecology)
• Nuclear Physics (Institute of Radiation Physics)

Funding

This project is partially funded by HZDR’s board of directors program for connecting different institutes by shared PhD students ("Vernetzungsdoktoranden").

Period

11/2024 - 10/2027

Abstract

High-entropy alloys (HEAs) and compositionally complex alloys (CCAs) with near-equiatomic compositions represent a novel class of materials with exceptional mechanical, thermo-mechanical, and corrosion-resistant properties, showing significant potential for applications in extreme environments, such as nuclear fusion and fission. This study investigates the irradiation tolerance of the fcc Cantor alloy (CoCrFeMnNi) and its Co-free derivatives, using a combination of broad and focused ion beam irradiation experiments at the HZDR Ion Beam Center (IBC) under various fluencies and temperatures. Focused-ion-beam (FIB) He-ion irradiation will explore surface morphology changes at high fluencies relevant to fusion reactors, while broad-beam self-ion irradiation will assess defect formation and mechanical property changes. Defect evolution will be analyzed using positron annihilation spectroscopy (PAS) and (scanning) transmission electron microscopy ((S)TEM), while nanoindentation will provide insights into the mechanical properties of the irradiated materials. Additionally, post-irradiation annealing will be employed to investigate defect stability. The results of this work will contribute to a deeper understanding of the irradiation behavior of HEAs, offering valuable insights for evaluating their suitability for nuclear applications.