Designing Irradiation-Resistant Concentrated Solid Solution Alloys by Tunning Lattice Distortion

Project: Research

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Description

High-entropy alloys (HEAs) comprised of multiprincipal elements have attracted extensive attention due to their excellent mechanical properties and promising irradiation resistance. It has been well established that the irradiation response of HEAs depends highly on the alloy compositions contributed by the extreme chemical disorder, which includes chemical complexity and site-to-site displacement. On the one hand, chemical disorder enhances carrier scattering, resulting in delayed energy dissipation. On the other hand, disorder induces a rough energy landscape for defect motion, suppressing defect aggregation and defect reactions. Nonetheless, these correlations are not directly related to the alloy compositions, and it is difficult to guide elemental selection and HEA design experimentally.In HEAs, the current theory suggests that their mechanical strength can be dictated by lattice distortion. By maximizing the lattice distortion effects by choosing elements with distinct atomic sizes, high-strength HEAs can be achieved due to the enhanced interactions between constituent elements and dislocations. Therefore, lattice distortion is a critical parameter in HEAs to affect defect properties. Unexpectedly, our preliminary simulations in our developed concentrated alloys with unprecedently high lattice distortions suggest that maximizing lattice distortion may not be beneficial to improve irradiation resistance. Leveraged on these findings, in this proposal, we intend to study the role of lattice distortion on the irradiation resistance HEAs, revealing the correlation between defect evolution and atomic size mismatch.To achieve this goal, we will combine atomistic simulations with experiments to study the irradiation response of a series of single-phase concentrated alloys with tunable lattice distortion. We would like to address the following critical issues if the project could be funded: (1) How does lattice distortion affect thermal and mass transport properties in HEAs? (2) How does lattice distortion determine the irradiation response of HEAs in the primary damage stage and long damage evolution phase? (3) Is there a systematic way that helps us identify irradiation-resistance HEAs by targeting desired lattice distortion, which is a fundamental property of HEAs? In the long run, we envision that our research may stimulate further interest in the design of irradiation-tolerant HEAs through tangible factors for structural materials applications. The outcome will also provide new understandings behind the irradiation performance of a wide range of conventional alloys, such as stainless steel. 

Detail(s)

Project number9043676
Grant typeGRF
StatusActive
Effective start/end date1/01/25 → …