CX-270389: Radiation Resistant High Entropy Alloys for Fast Reactor Cladding Applications – University of Wisconsin

The University of Wisconsin proposes to investigate the radiation damage performance of high entropy alloys (HEA) as promising “out of the box” class of metallic materials for sodium-cooled fast reactor (SFR) cladding and other in-core applications. The focus will be on radiation damage effects on the microstructure in this class of alloys at high temperatures and dpa (displacements per atom) levels, but this project will also include mechanical property measurements of irradiated layers (up to operational temperatures) and corrosion performance of the alloys in high temperature liquid sodium environment. To accomplish the proposed research in-depth and within the time-lines of the project, two types of HEAs, one based on 3d transition metals CrFeMnNi (face centered cubic structure) and the other based on light refractory metals NbTaTiVZr (body centered cubic structure) will be investigated. The alloys will be prepared by various processes, including arc melting, vacuum induction melting and field assisted sintering, which are available across the partnering institutions, and the processes yielding the most promising microstructures will be used for irradiation studies. Irradiations will be performed using protons, heavy ions, and dual beam (He + heavy ion) irradiations over a range of temperatures and dpa levels, intended to induce a wide range of irradiation damage mechanisms in the alloys. Precise mesoscale and nano-structural and nano-compositional characterizations and mechanical properties assessments will be performed.