A thermal fluid dynamics framework applied to multi-component substrates experiencing fusion and vaporisation state transitions
A thermal fluid dynamics framework applied to multi-component substrates experiencing fusion and vaporisation state transitions
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DOI：
10.1038/s42005-020-00462-7
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发表时间：
2020-11-03
影响因子：
5.5
通讯作者：
Smith, Michael C.
中科院分区：
文献类型：
--
作者：
Flint, Thomas F.;Scotti, Lucia;Smith, Michael C.
在极端条件下对多组分合金系统的动力学进行建模并预测其组成是一项复杂的任务。在这里，作者建立了一个理论框架来预测电子束焊接过程中多组分流动中的汽化和冷凝，并演示了这些过程是如何导致化学异质的。在高能量密度热源作用下，多组分合金系统的流体动力学在很大程度上决定了局部成分、组织和材料性能。在这项工作中，提出了一个多组分热流体动力学框架，用于预测合金系统由于熔化、汽化、冷凝和凝固现象而产生的发展。在连续性方程中引入了体积膨胀项来解释液体和汽体之间的密度跃迁，通过汽化和冷凝状态的变化来守恒质量。考虑了质量扩散、表面张力、表面张力与温度的关系、浮力项和潜热效应。该框架被应用于描述二元蒸气向非均相二元液体的塌缩，以及高能量密度功率束的加入应用，其中给出了优先元素蒸发的严格的数学描述。
Modelling the dynamics of multi-component alloy systems under extreme conditions and predicting the resulting compositions is a complex task. Here, the authors develop a theoretical framework to predict vaporisation and condensation in multi-component flows during electron beam welding and demonstrate how these processes lead to chemical heterogenisation.The fluid dynamics of multi-component alloy systems subjected to high energy density sources of heat largely determines the local composition, microstructure, and material properties. In this work a multi-component thermal fluid dynamics framework is presented for the prediction of alloy system development due to melting, vaporisation, condensation and solidification phenomena. A volume dilation term is introduced into the continuity equation to account for the density jump between liquid and vapour species, conserving mass through vaporisation and condensation state changes. Mass diffusion, surface tension, the temperature dependence of surface tension, buoyancy terms and latent heat effects are incorporated. The framework is applied to describe binary vapour collapse into a heterogeneous binary liquid, and a high energy density power beam joining application; where a rigorous mathematical description of preferential element evaporation is presented.