Unexpected nucleation mechanism of T1 precipitates by Eshelby inclusion with unstable stacking faults

Autor: Shuo Wang, Junsheng Wang, Chengpeng Xue, Xinghai Yang, Guangyuan Tian, Hui Su, Yisheng Miao, Quan Li, Xingxing Li
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: Materials Genome Engineering Advances, Vol 2, Iss 2, Pp n/a-n/a (2024)
Druh dokumentu: article
ISSN: 2940-9497
2940-9489
DOI: 10.1002/mgea.33
Popis: Abstract Aluminum‐lithium (Al‐Li) alloy is one of the most promising lightweight structural materials in the aeronautic and aerospace industries. The key to achieving their excellent mechanical properties lies in tailoring T1 strengthening precipitates; however, the nucleation of such nanoparticles remains unknown. Combining atomic resolution HAADF‐STEM with first‐principles calculations based on the density functional theory (DFT), here, we report a counterintuitive nucleation mechanism of the T1 that evolves from an Eshelby inclusion with unstable stacking faults. This precursor is accelerated by Ag‐Mg clusters to reduce the barrier, forming the structural framework. In addition, these Ag‐Mg clusters trap the free Cu and Li to prepare the chemical compositions for T1. Our findings provide a new perspective on the phase transformations of complex precipitates through solute clusters in terms of geometric structure and chemical bonding functions.
Databáze: Directory of Open Access Journals
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