Solidification behavior of nanoscaled tri-phasic bismuth-indium-tin alloy particles embedded in Al-Cu-Fe quasicrystalline matrix

The present manuscript aims to understand the solidification and alloying behavior of the nanoscaled multiphase Bi-In-Sn nanoparticles embedded in the icosahedral quasicrystalline (IQC) matrix, synthesized using the melt spinning route. Detailed transmission electron microscopy (TEM) investigation reveals the formation of three distinct phases; tetragonal BiIn, rhombohedral (Bi), hexagonal (gamma-Sn) or tetragonal (beta-Sn) within the nanoparticles depending on the size. It also shows that BiIn and (Bi) exhibit a reasonably good lattice match with the IQC matrix, whereas (gamma-Sn) does not obtain any orientation relationship with sur-rounding IQC. The DSC investigations show a sharp melting peak, whereas no distinct exothermic peak was observed on cooling, indicating solidification occurring over a range of temperatures. To investigate the extent of undercooling required for solidification, careful cyclic heating, and cooling experiments were performed in the DSC. The results suggest that the nanoparticles can completely be solidified by cooling to -160 degrees C, indicating extensive undercooling required for solidification. In-situ XRD during cooling depicts that the solidification is triggered by the nucleation of the primary (Bi) phase at 0 degrees C. Careful thermodynamic modeling of the Bi-In-Sn system with different nano-sizes were evaluated to interpret the size-dependent solidification behavior of the nanoalloy particles. The experimental results can be compared with the calculated nanophase diagram, presenting a reasonably good match. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

TEM investigation revealed the formation of three distinct phases within the nanoparticles; DSC analysis showed a sharp melting peak but no distinct exothermic peak during cooling; experimental results indicated extensive undercooling is required for complete solidification of the nanoparticles.