Floating Grain Formation and Macrosegregation in a 2024 Al Alloy Prepared by Hot-Top DC Casting with a 2024 Al Alloy Insert

Zhu, Cheng; Zhao, Zhihao; Zhu, Qingfeng; Wang, Gaosong; Li, Xudong; Zuo, Yubo; Dong, Hanchun; Qin, Gaowu

doi:10.1007/s11661-021-06304-7

Cited by 9 publications

(4 citation statements)

References 23 publications

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“…16,17 It is found that for KDP crystals containing Mg ions, DFT indicated that the absorption peak locates at 4.37 eV (284 nm) in PE-KDP, and the absorption peak locates at 4.66 eV (266 nm) in FE-KDP, by DFT. 18 A large lattice distortion (9.26-22.33%) in H-O bonds induced by Ba K defects was found in paraelectric phase KDP crystals. 19 The linear absorption spectra indicate that the presence of Al 3+ ions minimally impacts the linear absorption of the KDP crystals.…”

Section: Introductionmentioning

confidence: 96%

Influence of Cr³⁺ cluster defects on crystal structure and optical properties of KDP crystals studied by DFT and UV-Vis

Li,

Zhang,

Sun

et al. 2024

Mater. Adv.

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Section: Introductionmentioning

confidence: 96%

Influence of Cr³⁺ cluster defects on crystal structure and optical properties of KDP crystals studied by DFT and UV-Vis

Li,

Zhang,

Sun

et al. 2024

Mater. Adv.

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“…7,9) In addition to solidification shrinkage, the movement of floating grains contributes to negative centerline segregation. [10][11][12][13] Moreover, the appearance of floating grains deteriorates the evenness of the grain structure. 12,14) Although several studies have investigated the effect of casting speed on the as-cast structure and macrosegregation, the effect on floating grains is yet to be clarified.…”

Section: Introductionmentioning

confidence: 99%

Effect of Casting Speed on Floating Grains in Direct-Chill Casting of Aluminum Alloys

Zhang,

Ling,

Yao

et al. 2023

Mater. Trans.

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The effects of casting speed on macrosegregation and grain structure during the direct-chill casting of an Al-Mg-Si alloy are experimentally investigated. Results show that increasing the casting speed yields a more pronounced negative centerline segregation. Regard this mechanism, apart from the increased contribution of solidification shrinkage, the variation in floating grains is newly observed. The increased casting speed significantly increases the size and fraction of floating grains at the central portion of the billet, thus resulting in a more severe negative segregation. To clarify the experimentally observed phenomena, the solidification and distribution of floating grains in billets cast at different casting speeds are numerically simulated. The increased casting speed deepens the slurry zone significantly, thus providing more time for the floating grains to freely float and develop before settling into the mushy zone. Additionally, the greater slope of the coherency isotherm resulting from the increased casting speed promotes the movement and sedimentation of the floating grains toward the central portion of the billet. Consequently, more floating grains are detected at the billet center.

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“…For example, polymer-grafted nanoparticles can control the directionality and local density of entanglements, resulting in crazing during stress (12,13). Major advancements have been made by improving the network perfection in gels, which differ from polymer solids forming the basis for most plastic products (14,15).…”

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confidence: 99%

The propensity for covalent organic frameworks to template polymer entanglement

Neumann,

Kwon,

Gropp

et al. 2024

Science

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The introduction of molecularly woven three-dimensional (3D) covalent organic framework (COF) crystals into polymers of varying types invokes different forms of contact between filler and polymer. Whereas the combination of woven COFs with amorphous and brittle polymethyl methacrylate results in surface interactions, the use of the liquid-crystalline polymer polyimide induces the formation of polymer-COF junctions. These junctions are generated by the threading of polymer chains through the pores of the nanocrystals, thus allowing for spatial arrangement of polymer strands. This offers a programmable pathway for unthreading polymer strands under stress and leads to the in situ formation of high-aspect-ratio nanofibrils, which dissipate energy during the fracture. Polymer-COF junctions also strengthen the filler-matrix interfaces and lower the percolation thresholds of the composites, enhancing strength, ductility, and toughness of the composites by adding small amounts (~1 weight %) of woven COF nanocrystals. The ability of the polymer strands to closely interact with the woven framework is highlighted as the main parameter to forming these junctions, thus affecting polymer chain penetration and conformation.

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Floating Grain Formation and Macrosegregation in a 2024 Al Alloy Prepared by Hot-Top DC Casting with a 2024 Al Alloy Insert

Cited by 9 publications

References 23 publications

Influence of Cr³⁺ cluster defects on crystal structure and optical properties of KDP crystals studied by DFT and UV-Vis

Influence of Cr³⁺ cluster defects on crystal structure and optical properties of KDP crystals studied by DFT and UV-Vis

Effect of Casting Speed on Floating Grains in Direct-Chill Casting of Aluminum Alloys

The propensity for covalent organic frameworks to template polymer entanglement

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Floating Grain Formation and Macrosegregation in a 2024 Al Alloy Prepared by Hot-Top DC Casting with a 2024 Al Alloy Insert

Cited by 9 publications

References 23 publications

Influence of Cr3+ cluster defects on crystal structure and optical properties of KDP crystals studied by DFT and UV-Vis

Influence of Cr3+ cluster defects on crystal structure and optical properties of KDP crystals studied by DFT and UV-Vis

Effect of Casting Speed on Floating Grains in Direct-Chill Casting of Aluminum Alloys

The propensity for covalent organic frameworks to template polymer entanglement

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Product

Resources

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Influence of Cr³⁺ cluster defects on crystal structure and optical properties of KDP crystals studied by DFT and UV-Vis

Influence of Cr³⁺ cluster defects on crystal structure and optical properties of KDP crystals studied by DFT and UV-Vis