Frenznick Sascha, Stratmann Martin, Rohwerder Michael
Max Planck Institut für Eisenforschung, Max-Planck-Strasse 1, 40273 Düsseldorf, Germany.
Rev Sci Instrum. 2008 Apr;79(4):043901. doi: 10.1063/1.2901539.
Reactive wetting plays a crucial role in many technical processes, from soldering in microelectronics, production of metal/ceramic composites, to hot dip galvanizing in mass production of zinc coated steel sheet. In all these cases the wetting behavior of metal melts on different surfaces plays a crucial role in material joining and coating. In all these processes the formation of the interfacial reaction layer has to occur within as short a time as possible in order to ensure a fast overall production speed. As the interfacial layer determines the stability of the formed composites, detailed knowledge of its growth mechanisms is required for a directed process optimization. However, the investigation of the processes occurring at the buried interface between substrate and wetting phase is difficult, especially for the case of liquid metal wetting metallic or ceramic solid substrates at high temperatures. Here, a novel advanced technique for the investigation of high temperature wetting processes up to a temperature of 1100 K is presented. It is based on the sessile drop technique but, in addition, allows spinning off the droplet at any chosen wetting time, thus providing direct access to the interfacial reaction layer. Since the experimental setup is integrated into a UHV compatible reaction chamber, not only excellent control of the composition of the atmosphere is ensured, but also direct transfer to surface analytical tools such as scanning electron microscope or electron spectroscopy for chemical analysis without intermediate exposure to air is realized. As will be shown for the case of hot dip galvanising of steel, this is an outstanding advance compared to existing methods.
反应性润湿在许多技术过程中起着关键作用，从微电子中的焊接、金属/陶瓷复合材料的生产，到镀锌钢板大规模生产中的热浸镀锌。在所有这些情况下，金属熔体在不同表面上的润湿行为在材料连接和涂层中起着关键作用。在所有这些过程中，界面反应层必须在尽可能短的时间内形成，以确保整体生产速度快。由于界面层决定了所形成复合材料的稳定性，因此为了进行有针对性的工艺优化，需要详细了解其生长机制。然而，研究在基底和润湿相之间的埋藏界面处发生的过程是困难的，特别是对于液态金属在高温下润湿金属或陶瓷固体基底的情况。在此，提出了一种用于研究高达1100 K温度的高温润湿过程的新型先进技术。它基于 sessile drop 技术，但此外，还允许在任何选定的润湿时间甩掉液滴，从而直接获得界面反应层。由于实验装置集成到一个与超高真空兼容的反应室中，不仅确保了对气氛成分的出色控制，而且还实现了直接转移到表面分析工具，如扫描电子显微镜或化学分析电子能谱，而无需中间暴露于空气中。正如将在钢的热浸镀锌案例中所示，与现有方法相比，这是一项杰出的进展。
