The Contribution of Diffusion Coefficient to the Eutectic Instability and Amorphous Phase Formation

Nan Wang; Xiao Wang; Wen Jing Yao

doi:10.4028/www.scientific.net/MSF.654-656.1355

Paper Titles

Heterogeneous Nucleation and Grain Formation on Spherical and Flat Substrates
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Researches on the Nucleation Behaviors of NH4Cl Crystal on Coarse Aluminum Surfaces
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Directional Solidification and Characterization of Al₂O₃/Er₃Al₅O₁₂ Eutectic In Situ Composite by Laser Zone Remelting
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Microstructure Evolution and Compression Properties of a Directionally Solidified Ni-24.8%Nb Hypereutectic Alloy
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The Contribution of Diffusion Coefficient to the Eutectic Instability and Amorphous Phase Formation
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Analysis of an Equiaxed Dendrite Growth Model with Comparisons to In-Situ Results of Equiaxed Dendritic Growth in an Al-Ge Alloy
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Modelling and Experiments Concerning Dendrite Re-Melting and Its Role in Microstructural Evolution in Spray Formed Ni Superalloys
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The Influence of External Mechanical Stresses on Agglomeration and Bending of Solidifying Crystals
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Undercooling Behavior and Solidification Microstructure Evolution of Sn-Cu-Ni Solders Modified by Minute Amount of Mixed Rare Earth La-Ce
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HomeMaterials Science ForumMaterials Science Forum Vols. 654-656The Contribution of Diffusion Coefficient to the...

The Contribution of Diffusion Coefficient to the Eutectic Instability and Amorphous Phase Formation

Abstract:

The diffusion coefficient D decides the diffusion length of solute boundary and plays a key role in the microstructure selection. This paper examines quantitatively the contribution of diffusion coefficient to the eutectic instability and amorphorization ability. The maximum growth velocity Vmax and the maximum undercooling Tmax as functions of activation energy Q in strong liquids are deduced theoretically based on eutectic growth model by separating Q from D. It reveals that the larger the Q, the smaller the Tmax and Vmax, which shows the same tendency as experimental values in some Al-based alloys and glass formers. This indicates that it is the sluggish movement of atoms that makes the transition from eutectic to others structural morphologies, even to amorphous phase, occur at smaller interface growth velocity or undercooling, which is the main contribution of the diffusion coefficient to the amorphorization ability.