Experimental Characterization and Sequential Multi-Scale Modeling of Reactive Wetting

Suny At Binghamton, Binghamton NY

Investigators

Abstract

TECHNICAL: Wetting, phase change and reaction in high temperature systems (e.g., a liquid metal on a metal substrate) are complex phenomena that are only partially understood. These phenomena are key to joining processes (soldering and brazing), thin film processing and sintering among others. Reactive wetting is characterized by chemical and physical processes that span a broad range of spatial and temporal scales. Effective study of reactive wetting requires a multi-disciplinary effort involving expertise in chemical thermodynamics, phase transformations, capillary behavior and multi-scale transport. PIs will undertake a comprehensive study involving experimental characterization of liquid metal sessile drops spreading on metallic substrates in a controlled environment for several important alloy systems. To gain better fundamental understanding and to more fully interpret the experimental results, three levels of computational modeling will be used. The modeling will simulate the relevant physical processes on different length and time scales. A framework of sequential multi-scale models provides a necessary foundation for the future development of more fully-coupled multi-scale models. The modeling and simulation in this study incorporate a quasi-one-dimensional diffusion model at the drop scale, a phase-field model coupled to hydrodynamic transport at the macro- and meso-scopic scales and molecular dynamics modeling of wetting and dissolution of high temperature metal-metal systems. A research group at Sandia National Laboratories will conduct atomistic simulations by applying their existing capability to model reactive wetting. The unique experimental characterization capabilities combined with the ability of the multi-scale models to quantify transport and contact line dynamics yields a significant advancement in the ability understand the complex phenomena associated with reactive wetting. NON-TECHNICAL: The innovative research will involve an experienced team of investigators (engineers, material scientists) and engineering students (both at the graduate and undergraduate level). The collaboration with Sandia National Laboratory will enable the students to interact with the research group performing the atomistic modeling. The investigators believe that this collaborative experimental/computational research effort will provide the students involved in the computational modeling valuable experience on how to incorporate knowledge gained from experimental characterization studies into continuum and first-principles models. The continuum level models will be developed using open-source software which will be available to students for use in studying related wetting and hydrodynamic phenomena and that can be extended to a range of applications.