Abstract
Material performance in extreme radiation environments is central to the design of future nuclear reactors. Radiation induces significant damage in the form of dislocation loops and voids in irradiated materials, and continuous radiation often leads to void growth and subsequent void swelling in metals with low stacking fault energy. Here we show that by using in situ heavy ion irradiation in a transmission electron microscope, pre-introduced nanovoids in nanotwinned Cu efficiently absorb radiation-induced defects accompanied by gradual elimination of nanovoids, enhancing radiation tolerance of Cu. In situ studies and atomistic simulations reveal that such remarkable self-healing capability stems from high density of coherent and incoherent twin boundaries that rapidly capture and transport point defects and dislocation loops to nanovoids, which act as storage bins for interstitial loops. This study describes a counterintuitive yet significant concept: deliberate introduction of nanovoids in conjunction with nanotwins enables unprecedented damage tolerance in metallic materials.
Highlights
Material performance in extreme radiation environments is central to the design of future nuclear reactors
Atomistic simulations reveal that nanotwins are essential to achieve superior radiation tolerance as twin boundaries (TBs) networks consisting of coherent TBs (CTBs) and incoherent TBs (ITBs) promote rapid migration of defect clusters to nanovoids, wherein they are annihilated
Nanovoids act as defect sinks to absorb radiation-induced interstitial loops, as revealed by in situ radiation and confirmed by molecular dynamics (MD) simulations
Summary
Material performance in extreme radiation environments is central to the design of future nuclear reactors. Irradiation of metals by neutrons or heavy ions results in a large number of point defects[7,8,9] and their clusters, including dislocation loops, voids and stacking fault tetrahedra[10,11,12,13,14,15], which cause severe void swelling, radiation hardening, embrittlement and creep[16,17,18] Interfacial defect sinks, such as grain boundaries[19,20,21,22,23], heterophase interfaces[24,25,26,27,28] and free surfaces[29,30,31], have proven to be effective in alleviating radiation damage. This study provides a fresh perspective on the design of metallic materials with extraordinary damage tolerance
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.