Collaborative Research: Wetting of Liquid Metals on Rough Surfaces

合作研究：液态金属在粗糙表面上的润湿

• 批准号: 1234581
• 负责人: Sinisa Mesarovic
• 金额: $ 18.34万
• 依托单位: Washington State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-01 至 2016-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1234581&HistoricalAwards=false
• 关键词: Collaborative; Research; Wetting; Liquid; Metals

1235757 / 1234581PI: Sekulic / MesarovicSpreading of liquids over solid surfaces is ubiquitous in nature and is the key aspect of many industrial processes, such as low temperature soldering, high temperature brazing, de-icing, organic liquid imbibing, etc. For example, in the case of brazing/soldering, the tight time scheduling of the processing combined with dissimilar wetting properties of materials being joined and a possible variability of temperature during spreading, require a precise control, which in turn requires quantitative prediction tools. The major difficulties in predicting such a complex flow include: (1) roughness of the spreading surface, (2) chemical reactions between the liquid/melt and the substrate, and, (3) inadequate models of the physical mechanism by which the triple line (a locus of points where solid, liquid and vapor/gas meet) propagates. This project will integrate experimental and modeling strategy through: (i) experiments on characterized virgin and designed surfaces, with in situ monitoring and measurements of the triple line motion, (ii) advances in theory and modeling based on the diffuse interface (phase-field) models, capable of representing propagation of phase- and chemical reaction fronts, as well as the diffusive nature of the triple line motion, and, (iii) integration of modeling and experiments. Real time in situ monitoring of the spreading at the micro scale around the triple line will be the source of data on kinetics of the liquid front propagation. To achieve projects objectives, the phase-field modeling for reactive and non-reactive spreading will be implemented within a versatile computational finite element framework, thus enabling studies of variety of problems with different geometries. The major experimental challenges are related to the fast evolution of the triple line and the presence of reactive substrates. The required time resolution will be achieved by developing hot stage microscopy techniques for in situ monitoring of the moving liquid front and the dynamics of the contact angle. Suppression of a chemical reaction will be accomplished by formation of intermetallics prior to spreading of a liquid metal. The major modeling challenges include: (a) implementation of the surface diffusion kinetics governing the motion of the triple line for the non-reactive model into the finite element framework to model rough surfaces, and, (b) implementation of the combined liquid-gas phase-field and the chemical reaction phase-field into the finite element framework.The impact of this investigation will be felt in a broad set of applications, related to industrial and natural processes. The transformative nature of the research is that it will results in the ability to effectively control wetting by surface alterations and the selection of liquid system and solid substrates. This will enable rational design of industrial processes which depend on liquid spreading, and products whose function depends on wetting.

1235757 / 1234581PI：Sekulic / Mesarovic 液体在固体表面上的扩散本质上是普遍存在的，并且是许多工业过程的关键方面，例如低温焊接、高温钎焊、除冰、有机液体吸入等。在钎焊/锡焊的情况下，加工时间安排紧迫，加上所连接材料的润湿特性不同，以及可能的情况传播过程中温度的变化需要精确的控制，这反过来又需要定量预测工具。 预测如此复杂的流动的主要困难包括：（1）铺展表面的粗糙度，（2）液体/熔体与基材之间的化学反应，以及（3）三重线所依据的物理机制模型不充分（固体、液体和蒸气/气体相遇的点的轨迹）传播。 该项目将通过以下方式整合实验和建模策略：（i）对特征原始和设计表面进行实验，并进行三线运动的原位监测和测量，（ii）基于扩散界面（相场）的理论和建模进展）模型，能够表示相和化学反应前沿的传播，以及三线运动的扩散性质，以及，（iii）建模和实验的集成。 对三重线周围微尺度扩散的实时原位监测将成为液体前沿传播动力学数据的来源。 为了实现项目目标，反应性和非反应性扩散的相场建模将在通用计算有限元框架内实施，从而能够研究具有不同几何形状的各种问题。 主要的实验挑战与三线的快速演化和反应性底物的存在有关。 所需的时间分辨率将通过开发用于原位监测移动液体前沿和接触角动态的热台显微镜技术来实现。 化学反应的抑制将通过在液态金属扩散之前形成金属间化合物来实现。 主要的建模挑战包括：(a) 将控制非反应模型三重线运动的表面扩散动力学实现到有限元框架中以模拟粗糙表面，以及 (b) 实现液-气组合将相场和化学反应相场纳入有限元框架。这项研究的影响将在与工业和自然过程相关的广泛应用中感受到。 该研究的变革性本质在于，它将带来通过表面改变以及液体系统和固体基质的选择来有效控制润湿的能力。 这将使依赖于液体扩散的工业过程以及功能依赖于润湿的产品的合理设计成为可能。