b'Multi-role High Entropy AlloysNovel microstructural design and manufacturing of high entropy alloys establish for Extreme Environmentsa new paradigm for developing materials that operate in thermal and mechanical extreme environments.N uclear, fossil, and solar power generation systems need materials capable of operating for several decades while maintaining adequate strength at temperatures approaching or exceeding 800C. The emerging class of high entropy alloys have the potential to be tailored for these extreme environments. This PROJECT NUMBER:project implemented a calculation of phase diagram based approach to accelerate 20A44-011 exploration of multi-role high entropy alloy compositions that would exhibit desired microstructure properties for basic fuel saving (fossil), output application (nuclear TOTAL APPROVED AMOUNT:co-generation), and making systems technically feasible (solar). Novel solid-state $885,500 over 3 years transformation pathways such as structural hierarchy in ordered precipitates have PRINCIPAL INVESTIGATOR:been explored in a body-centered cubic based high entropy alloy via coupled Subhashish Meher advanced characterization and phase field modeling. The results suggest that the high temperature precipitate coarsening can be delayed significantly due to structural CO-INVESTIGATORS: hierarchy. Also, the intriguing aspect of selective coarsening and dissolution of ordered Guoping Cao, INL precipitates in high entropy alloys when subjected to high temperatures was understood Michael Glazoff, INLvia advanced microscopy and phase field modeling. This project utilized state-of-Prabhat Tripathy, INLthe-art characterization and experimental facilities at INL and Center for Advanced Thomas Lillo, INL Energy Studies to understand the collective mechanical response of high entropy alloys under coupled thermal and mechanical extremes. Furthermore, high entropy alloy manufacturing from oxide powder mixtures was demonstrated via a novel cost-effective electro-deoxidation method. This new experimental capability will be essential for the future scaling of this process for larger production of alloy powders. The exploration of high temperature high entropy alloys with novel microstructural design and manufacturing provides a solid foundation for a new paradigm of alloy design required for operation in coupled thermal and mechanical extremes associated with advanced nuclear reactors.TALENT PIPELINE:Sanu Gupta, student at Oregon State UniversitySourabh Kadambi, postdoc at INLA representation of coupled experimental and modeling implemented in the project for physical understanding of high entropy alloys.78'