基于分子动力学的液相金属/固相陶瓷反应润湿行为及机理研究

Reaction wettability of Liqud-metal/Solid-ceramic is the decisive factor in influencing their interfacial combined property, and the behavior and mechanism of reactive wetting are the critical theoretical basis for the material preparation and processing technologies, such as metal-ceramic composites fabricating and ceramic joining. In this project, the molecular dynamics calculation will be the method, the AgCuTi/SiC and CuNiTi/SiC reaction wetting systems will be the research objects, the investigate on thermodynamics and dynamics behavior of wetting interface will be the principal line, the normalized analysis for the various wetting-influences factors will be the link, to investigate the behavior and mechanism of Liqud-metal/Solid-ceramic reactive wetting. The specific research contents as follows: wetting spreading characteristic and wetting interface evolution regular for reaction wetting system, free energy release and interfacial energy variation behaviors caused by wetting interface chemical reaction, the normalized analysis for the various wetting-influences factors and the synergy effect investigation for them to the reaction wetting behavior. .The investigation on behavior and mechanism of Liqud-metal/Solid-ceramic reactive wetting, which is based on the molecular dynamics theory, has not been reported before. The Liqud-metal/Solid-ceramic reactive wetting interface molecular dynamics model building and the relevant research methods proposed in this project can generally apply to the interface process researches in the field of materials science.

研究意义和内容：液相金属/固相陶瓷的反应润湿性是影响二者界面结合性能的决定性因素，其反应润湿行为及相关机理是金属陶瓷复合材料合成和陶瓷连接等材料制备/加工技术的关键理论基础。本项目拟基于分子动力学方法，以典型的AgCuTi/SiC和CuNiTi/SiC反应润湿体系为对象，以润湿界面热力学与动力学行为研究为主线，以反应润湿影响因素归一化分析为桥梁，对液相金属/固相陶瓷反应润湿行为及机理进行研究，具体包括：反应润湿体系的润湿铺展特性与润湿界面演化规律；润湿界面反应诱发的自由能释放与界面能变化行为；反应润湿影响因素归一化及其对反应润湿行为的协同影响效应。.项目特色与创新：基于分子动力学理论的液相金属/固相陶瓷反应润湿行为及机理研究国内外尚未见报道；项目提出的液相金属/固相陶瓷反应润湿界面分子动力学模型构建及相关研究方法对材料科学领域界面过程的研究具有普遍意义。

液相金属/固相陶瓷的反应润湿性是影响二者界面结合性能的决定性因素，反应润湿行为及相关机理是金属陶瓷复合材料合成和陶瓷连接等材料制备/加工技术的关键理论基础。本项目围绕这一主题，首先研究了液相金属/固相陶瓷反应润湿体系的润湿铺展特性与润湿界面演化规律，发现随着活性元素含量的增加，液相金属表面张力逐步升高，其在固相陶瓷上铺展时间延长并导致界面化合物厚度呈增加趋势，但最终润湿性显著改善；而后，基于分子动力学方法，构建了液相金属/固相陶瓷的微观模型，并对界面化学反应引起的自由能释放和界面能变化进行了计算，发现在不同活性元素含量的反应润湿体系中，单位界面反应释放的自由能相差不大,而界面能变化随着活性元素化学势的升高迅速增加，且化学反应生成的界面化合物表面能越高，则液/固界面能越低，引起的界面能变化越为显著；最后，对反应润湿影响因素进行了归一化处理及并分析了各因素对反应润湿性的协同影响效应，结果表明，液相金属/固相陶瓷反应润湿体系的最终润湿性受到液/固界面能变化，即界面化合物表面能的决定性影响，界面化学反应引起的自由能释放对反应润湿体系的润湿动力学起到推进作用但是对最终润湿性并未起到明显的影响。