Alloy solidification: Assessment and improvement of an easy-to-apply model  

作　　者：H.Liu Y.Liu S.L.Lu Y.Zhang H.Chen Y.Chen M.Qian 

机构地区：[1]School of Materials Science and Engineering,Southwest Jiaotong University,Chengdu 610031,China [2]Centre for Additive Manufacturing,School of Engineering,RMIT University,Melbourne,VIC 3000,Australia [3]School of Materials Science and Engineering,Sichuan University,Chengdu 610065,China

出　　处：《Journal of Materials Science & Technology》2022年第35期1-11,共11页材料科学技术（英文版）

基　　金：funding from the Australian Research Council(ARC) via DP180103205。

摘　　要：It has been a central task of solidification research to predict solute microsegregation. Apart from the Lever rule and the Scheil-Gulliver equation, which concern two extreme cases, a long list of microsegregation models has been proposed. However, the use of these models often requires essential experimental input information, e.g., the secondary dendrite arm spacing(λ), cooling rate( ˙T) or actual solidification range(△T). This requirement disables these models for alloy solidification with no measured values for λ,˙T and △T. Furthermore, not all of these required experimental data are easily obtainable. It is therefore highly desirable to have an easy-to-apply predictive model that is independent of experimental input,akin to the Lever rule or Scheil-Gulliver model. Gong, Chen, and co-workers have recently proposed such a model, referred to as the Gong-Chen model, by averaging the solid fractions(f_(s)) of the Lever rule and Scheil-Gulliver model as the actual solid fraction. We provide a systematic assessment of this model versus established solidification microsegregation models and address a latent deficiency of the model, i.e.,it allows the Lever rule solid fraction fsto be greater than one(f_(s)> 1). It is shown that the Gong-Chen model can serve as a generic model for alloy solidification until fsreaches about 0.9, beyond which(f_(s)> 0.9) its applicability is dictated by both the equilibrium solute partition coefcient(k) and the solute diffusion coefcient in the solid(Ds), which has been tabulated in detail.

关 键 词：SOLIDIFICATION MICROSEGREGATION SOLUTE Back diffusion Eutectic formation 

分 类 号：TG111.4[金属学及工艺—物理冶金]