About this Abstract |
| Meeting |
MS&T26: Materials Science & Technology
|
| Symposium
|
Additively Manufactured Materials for Nuclear Energy
|
| Presentation Title |
Additive Manufacturing of Novel Cobalt-Free Nanoprecipitate-Strengthened High-Entropy Alloys for Nuclear Applications |
| Author(s) |
Nastaran Motaharinia, Matthew Luebbe, Fan Zhang, Haiming Wen |
| On-Site Speaker (Planned) |
Nastaran Motaharinia |
| Abstract Scope |
High-entropy alloys (HEAs) show promising properties, but cobalt-containing compositions are unsuitable for nuclear applications due to neutron activation. This study investigates a cobalt-free, nanoprecipitate-strengthened (Fe₀.₃Ni₀.₃Mn₀.₃Cr₀.₁)₈₈Ti₄Al₈ HEA produced by laser powder-bed fusion followed by thermal aging, with emphasis on irradiation-induced microstructural evolution and effects of the pre-existing nanoprecipitates on irradiation resistance. The samples were irradiated up to 10 displacements per atom at room temperature, 500 °C, and 700 °C. Atom probe tomography and transmission electron microscopy reveal that as-printed material accumulates significantly more irradiation defects than the aged, nanoprecipitates-containing counterpart. This improvement is attributed to a high number density of L1₂ nanoprecipitates, which act as defect sinks and stabilize the microstructure. Increasing irradiation temperature further suppresses defect accumulation but drives precipitate coarsening and elemental redistribution, particularly Fe/Cr depletion from L1₂ nanoprecipitates. These results demonstrate that the nanoprecipitates enhance irradiation resistance of HEAs, offering a pathway to next-generation nuclear structural materials. |