Abstract When an Al-droplet is in contact with an Au-solid substrate, the liquid phase reacts with the substrate and an intermetallic layer is formed at the solid-liquid interface due to diffusion and reaction. This phenomenon has been commonly observed in the soldering process and the wetting is termed as reactive wetting, in contrast to the inert wetting where the droplet does not react with the base materials and the substrate is flat. Young's law can be used to interpret the contact angle in the static state, but is not able to predict the dynamics in the process of reactive wetting. In this work, we present a multi-phase model including phase transition and fluid dynamics to investigate the effect of the formation of the intermetallic Al2Au phase and capillary flow on the reactive wetting in the Al-Au system. In order to capture phase boundaries of solid-, liquid- and intermetallic-vapor, phase-field simulations are performed based on a ternary (Al-Au-X) phase diagram concept and using experimental data. It has been found that the increase of both the liquid-intermetallic interfacial tension as well as the capillary flow lead to an inhibition effect for the growth of the intermetallic phase.

中文翻译：

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Al-Au 系统中金属间化合物 Al 2 Au 相的反应润湿和生长的相场模型

摘要 当Al液滴与Au-固体基体接触时，液相与基体发生反应，通过扩散和反应在固液界面形成金属间化合物层。这种现象在焊接过程中很常见，润湿被称为反应润湿，与惰性润湿相反，在惰性润湿中，液滴不与基材发生反应，基板是平坦的。杨氏定律可用于解释静态接触角，但不能预测反应润湿过程中的动力学。在这项工作中，我们提出了一个多相模型，包括相变和流体动力学，以研究金属间 Al2Au 相的形成和毛细管流动对 Al-Au 系统中反应润湿的影响。为了捕捉固体、液体和金属间蒸气的相边界，基于三元 (Al-Au-X) 相图概念并使用实验数据进行相场模拟。已经发现，液体-金属间界面张力以及毛细管流动的增加导致对金属间相生长的抑制作用。