NSUF 24-4928: Examination of ion irradiated Additive Friction Stir Manufactured metastable high entropy alloy

In order to enhance the long-term viability and competitiveness of the existing fleet and to develop an advanced reactor pipeline, it is essential to utilize innovative manufacturing methods/advanced materials for nuclear applications. “Enabling technologies” such as laser and electron beam-based fusion additive manufacturing (AM) and friction stir welding have caught the attention as a modular manufacturing technology to enable a more rapid and streamlined on-site fabrication process for large meter-scale fully dense nuclear structural components. In the last decade advancing solid-state manufacturing technologies like Additive Friction Stir Deposition (AFSD) proved to be a highly efficient substitute for fusion-based AM techniques. AFSD process is a robust, scalable (high build rate), faster, cheaper, and more reliable fabrication route leading to a defect-free dense build, aiding the Nuclear Energy Enabling Technology (NEET) Crosscut program to accelerate the construction of nuclear plants. Despite the increasing interest in solid-state processing, relatively limited studies have reported the irradiation performance of materials processed via solid-state additive manufacturing, to be considered for nuclear applications. Ion irradiation of AFSD Austenitic 316 stainless steel (SS) was recently studied where refined grain size resulted in increased sink sites for RIDs and thus resulted in no voids, decreased density of dislocation loops and networks, coarser solute cluster, and weaker radiation-induced segregation, as compared to the 316SS feed rod and 316SS processed via different conventional and fusion-based AM routes. High entropy alloys (HEAs) are potential candidates for nuclear applications, due to their promising mechanical properties and corrosion resistance. Several HEAs are reported to have superior irradiation resistance as compared to conventional alloys with noteworthy observation of absence or limited-presence irradiation-induced voids due to increased compositional complexity. Low stacking fault energy transformation-induced plasticity (TRIP) HEAs are reported to exhibit a self-healing mechanism where irradiation-induced transformation is restrained by thermal aid, thus recovering the microstructure from irradiation damage and improving radiation tolerance. This work seeks to combine the above two effects to explore TRIP HEA with a novel self-healing effect as the novel material, processed via AFSD solid-state route for nuclear applications, directly addressing the DOE’s purpose of Advanced Methods and Manufacturing Technologies (AMMT) to improve the performance of current and Gen IV reactors along with targeting new reactors design like Next Generation Nuclear Plant, Advanced Reactors Concept and Small Modular rectors. The objective of this proposal is to understand the metastability of AFSD TRIP Fe38.5Mn20Co20Cr15Si5Cu1.5 (in at %) HEA with irradiation and explore it as a nuclear radiation-tolerant material for harsh environments. The investigations carried out to achieve this goal will be via (1) self-ion irradiations at temperatures relevant to multiple reactor concepts and closer to the maximum swelling temperature; (2) mechanical properties evaluation via nanoindentation to understand the irradiation hardening mechanism; (3) microstructural characterization using TEM and APT to examine irradiation-induced microstructural changes; (4) develop appropriate processing-structure-property-temperature-dose correlations for AFSD TRIP HEA; (5) understand and compare the irradiation response of AFSD TRIP HEA with a recently published work on AFSD 316SS that reported improved radiation tolerance.

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Поле	Стойност
Award Announced Date	2024-05-28T16:55:12.303
Awarded Institution	University of North Texas
Facility Tech Lead	Lin Shao, Yaqiao Wu
Irradiation Facility	Accelerator Laboratory
PI	Priyanka Agrawal
PI Email	[email protected]
Project Type	RTE
RTE Number	None