首页|Growth and structural transitions of core-shell nanorods in nanocrystalline Al-Ni-Y

Growth and structural transitions of core-shell nanorods in nanocrystalline Al-Ni-Y

扫码查看
? 2022Unique nanorod precipitates with a core-shell structure are found to nucleate from the grain boundaries of a bulk nanocrystalline Al-Ni-Y alloy fabricated via powder consolidation, contributing significantly to stabilization and strengthening. The local structure, chemistry, and evolution of these features during annealing are reported here. In the as-consolidated state, the nanorods can be either structurally ordered or disordered, yet a consistent chemical patterning is found where the core is primarily Al plus C while the shell is enriched with Y. As annealing time increases, more nanorods transform to an ordered structure as they coarsen while the core composition remains unchanged. In contrast, the shell chemistry transitions from Y-rich to Ni-rich with longer annealing treatments, most likely due to the different diffusivities of Y and Ni in Al. Moreover, a spatial and chemical correlation between the nanorods and amorphous complexions is observed, suggesting that these complexions serve as preferential nucleation sites.

annealingGrain boundary segregationGrain boundary structureNanocrystalline materialsPrecipitation

Lei T.、Xu M.、Rupert T.J.、Shin J.、Gianola D.S.

展开 >

Department of Materials Science and Engineering University of California

Materials Department University of California

2022

Scripta materialia

Scripta materialia

EISCI
ISSN:1359-6462
年,卷(期):2022.211
  • 4
  • 30