A numerical study of irregular eutectic in Al-Si alloys under a large undercooling

Ao, Xiaohui; Xia, Huanxiong; Liu, Jianhua; He, Qiwei; Lin, Shengxiang

doi:10.1016/j.commatsci.2020.110049

Cited by 16 publications

(7 citation statements)

References 32 publications

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“…55,56,58−61 The eutectic point of Al−Si alloys has been reported to shift to the high-Si side upon rapid cooling and solidification from solution. 61 The rapid solidification with an increasing cooling rate decreases the grain size of crystallized primary Al. In addition, increasing the cooling rate causes the eutectic Si crystallized in the resinous form to change from a coarse lamellar structure to fine particles.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…The microstructure of Al–Si alloys solidifying from the Al–Si liquid phase has been discussed in the literature, and the morphologies of primary Al, eutectic Al, eutectic Si, and primary Si are known to vary greatly depending on the solidification conditions (i.e., cooling and growth rates) and trace additions. ,,− The eutectic point of Al–Si alloys has been reported to shift to the high-Si side upon rapid cooling and solidification from solution Figure S5 shows cross-sectional SEM or backscattered electron (BSE) images and EDS results for the atomized Al 88 Si 12 , Al 81 Si 19 , and Al 75 Si 25 particles.…”

Section: Resultsmentioning

confidence: 99%

“…In hypereutectic Al–Si alloys (>12.6 wt % Si), lumpy primary Si crystallizes from the melt as it solidifies, and resinous eutectic Si crystallizes as well as eutectic Al. , Many studies have reported on the solidification microstructures of hypoeutectic, eutectic, and hypereutectic Al–Si alloys, − and the morphologies of primary Al, eutectic Si, and primary Si are known to vary significantly depending on the solidification conditions (i.e., cooling and growth rates) and Si composition. − When Al–Si alloys are rapidly solidified from solution as in gas atomization, the eutectic point shifts to the high-Si side . In other words, Al–Si alloy powders prepared by gas atomization have a microstructure consisting of primary Al, eutectic Si, and eutectic Al without crystallization of primary Si at hypereutectic Al–Si compositions. , Because of the rapid solidification, the grain size of primary Al decreases with increasing cooling rate at hypoeutectic and eutectic Al–Si compositions. Furthermore, the shape of the resinous eutectic Si crystallizes from a coarse lamellar structure to fine particles with increased eutectic supercooling .…”

Section: Introductionmentioning

confidence: 99%

“…In other words, Al–Si alloy powders prepared by gas atomization have a microstructure consisting of primary Al, eutectic Si, and eutectic Al without crystallization of primary Si at hypereutectic Al–Si compositions. , Because of the rapid solidification, the grain size of primary Al decreases with increasing cooling rate at hypoeutectic and eutectic Al–Si compositions. Furthermore, the shape of the resinous eutectic Si crystallizes from a coarse lamellar structure to fine particles with increased eutectic supercooling . Moreover, the primary Si, eutectic Al, and eutectic Si all become finer with an increased cooling rate in hypereutectic Al–Si alloys. , …”

Section: Introductionmentioning

confidence: 99%

“…56−59 When Al−Si alloys are rapidly solidified from solution as in gas atomization, the eutectic point shifts to the high-Si side. 61 In other words, Al−Si alloy powders prepared by gas atomization have a microstructure consisting of primary Al, eutectic Si, and eutectic Al without crystallization of primary Si at hypereutectic Al−Si compositions. 57,61 Because of the rapid solidification, the grain size of primary Al decreases with increasing cooling rate at hypoeutectic and eutectic Al−Si compositions.…”

Section: ■ Introductionmentioning

confidence: 99%

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Scalable Synthesis of Porous Silicon by Acid Etching of Atomized Al–Si Alloy Powder for Lithium-Ion Batteries

Kawaura

Suzuki

Kondo

et al. 2023

ACS Appl. Mater. Interfaces

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Si anodes have attracted considerable attention for their potential application in next-generation lithium-ion batteries because of their high specific capacity (Li15Si4, 3579 mAh g–1) and elemental abundance. However, Si anodes have not yet been practically applied in lithium-ion batteries because the volume change associated with lithiation and delithiation degrades their capacity during cycling. Instead of considering the active material, we focused on the structural design and developed a scalable process for producing Si anodes with excellent cycle characteristics while precisely controlling the morphology. Al–Si alloy powders were prepared by gas atomization, and porous Si with a skeletal structure was prepared by leaching Al using HCl. Porous Si (p-Si12, p-Si19) prepared from Al88Si12 and Al81Si19 comprised resinous eutectic Si, and porous Si (p-Si25) prepared from Al75Si25 comprised lumpy primary Si and resinous eutectic Si. The porosity of the Si anodes varied from 63% to 76%, depending on the Si composition. The p-Si19 anode displayed the finest pore distribution (20–200 nm), excellent rate characteristics, a reversible discharge capacity of 1607 mAh g–1 after 200 cycles at a rate of 0.1 C with a Coulombic efficiency of over 97%, and high stability. The performances of the p-Si25 and p-Si19 electrodes began to decrease after 250 and 850 cycles, respectively, with a constant-charge capacity of 1000 mAh g–1 and at a rate of 0.2 C. In contrast, the p-Si12 anode maintained its discharge capacity at 1000 mAh g–1 for up to 1000 cycles without degradation. Therefore, the developed manufacturing process is expected to produce porous Si as an active material in lithium-ion batteries for high capacity and long life at an industrial scale.

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Section: ■ Results and Discussionmentioning

confidence: 99%