The Formation of Nanoparticles and Their Competitive Interaction with Twins during Eutectic Si Growth.
MATERIALS 2018;
11:ma11081404. [PMID:
30103432 PMCID:
PMC6120016 DOI:
10.3390/ma11081404]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 08/01/2018] [Accepted: 08/08/2018] [Indexed: 11/16/2022]
Abstract
In order to investigate the competitive interaction between nanoparticles and twin, the eutectic Si microstructures in Al⁻10Si (wt. %) base alloys with exclusive and combined addition of Sr and Sb are characterized by combined TEM and atom probe tomography (APT). The chemical short range order in Sb⁻Sb and Sb⁻Sr pairs is revealed by ab initio molecular dynamics simulation, which promotes the formation of clusters and nanoparticles. The coexistence of nanoparticles and twins is observed in Sb containing alloys, with a negative correlation in the corresponding number density, owing to the competitive stacking of precursors and individual atoms at the solid⁻liquid interface. Large size particles around 70 nm with a uniform distribution of Sr atoms are formed in Al⁻10Si⁻0.35Sb⁻0.015Sr (wt. %) alloys, due to the precursor aggregation and homogeneous nucleation in the droplets that nucleation are depressed. A model for the formation of nanoparticles and their interaction with twins is proposed.
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