Berlin 2024 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 36: Liquid and Amorphous Materials I

MM 36.2: Vortrag

Mittwoch, 20. März 2024, 12:00–12:15, C 243

crack-healing mechanisms in high entropy alloys under ion irradiation — •qi xu, daniel sopu, and jürgen eckert — Erich Schmid Institute of Materials Science, Austrian Academy of Sciences, Jahnstraße 12, Leoben A-8700, Austria

High entropy alloys (HEAs) are potential candidate for advanced nuclear structural materials due to the outstanding mechanical properties and irradiation resistance in extreme conditions. However, micro-cracks, a common material damage, are introduced during the preparation and service processes, resulting in weakened structural integrity and irradiation resistance. In this work, an atomistic investigation of crack healing mechanisms in FeCoCrNiAl0.5 HEA under ion irradiation is provided by molecular dynamics (MD) simulations. Quantitative analysis of the point defect generation and recombination during the process of overlapping collision cascades are implemented to assess the irradiation response of cracked HEA. The interstitial defects generated in the core of the cascade during the first collision event diffuse to the crack surface, resulting in crack-healing during subsequent recrystallization. Additionally, the corresponding vacancies precipitate and form large-size vacancy clusters that generate stacking faults and complex dislocation networks distributed around the position of the healed crack. With increasing the number of overlapping cascades, the defects recombination rate increases and the phase stability is further improved. The crack healing engineering in HEA under ion irradiation could pave the way towards designing advanced nuclear materials.

Keywords: High entropy alloy; crack-healing; irradiation; point defects; Molecular dynamics