Wettability of Solid-Liquid Interface under Microgravity (Dynamic Behavior of Interface in Space)

在金属-陶瓷接头和复合材料的制备中，必须考虑润湿行为，以解决界面现象。特别是在太空中进行物质实验，需要对重力进行进一步的研究。近年来，人们提出并尝试了许多关于润湿性的实验方法和分析方法，但很大一部分方法都是在静态条件下进行的，没有摩擦力效应。由于这些试验都是在没有某些限制条件(动态条件、滞后、重力等)的情况下进行的，所以各试验之间的结果差别很大，重复性较差。为了观察地面和空间的润湿性，考虑到一些实验条件，我们提出了一些新的实验方法，并制作了实验装置。本文利用抛物线弹道飞行器在空间进行了生长滴法和液桥方法，并增加了Meniscogrph方法，包括…地面上的多层平板和平行平板方法。将结果进行比较，考察了重力对润湿性的影响。得到了以下结论：(1)生长滴法。在静态条件下，接触角取决于液滴的大小。进退接触角对生长速度有影响。润湿行为随重力水平的不同而不同。(2)液桥法。液桥形状随桥径比和固液界面润湿性的不同而不同。稳定状态下的接触角取决于重力水平。(3)半月板描记法。用理论流体力学方程分析了浸泡速度、粘度和滞后性对动态润湿行为的影响。氧化对熔融金属的润湿现象有较大影响。(4)斜板法和平行板法。静态接触角可以用TASE方法来估算，但与其他研究结果有一定的差异。(5)比较各种方法的结果。在地面上，生长滴法和半月板测量法得到的静态接触角值基本相同，液桥的结果与其他方法得到的减小接触角的结果基本一致。在微重力条件下，液桥法的静态接触角值大于另一个减小接触角的值。较少

In the fabrication of metal-ceramic joint and composite materials, the wettability behavior must be considered to solve the interface phemomena. Especially, the further studies about the gravity is required to carry out the material experiments in space. Recently, many experimental procedures and analysis have been proposed and tried about the wettability, but a large part of methods have been operated only about the static condition without the bravityeffects. As these tests were made without some expeimetal conditions (dynamic condition, hysteresis, gravity ect.), the results had much difference and a few reproducibility among each tests. In order to observe the wettability in ground and space with considering the some experimental conditions, we proposed some new experimental methods and made the apparatus.In this paper, I carried out the Growing Drop Method and Liquid Bridge Methods in space using an aircraftflyingparabollic ballictic trajectories and added Meniscogrph Method, Incl … More ined Plate and Parallel Plate methods on ground. The results were compared each other and it investigated that the effects of gravity on the wettability.The following conclusions were obtained :(1) Growing Drop Method. Contact angle was depended on the drop size at static condition. Advancing and receding contact angle was affected on growing speed. Wetting behaviors varied with a gravity level.(2) Liquid Bridge Method. Liquid bridge shapes varied with the bridge aspect ratio and wettability onsolid-liquid interface. Contact angle at stable condition depended on the gravity level.(3) Meniscograph Method. Dynamic wetting behaviors were analyzed with a thoritical fluid mechanic equations and depended on the immersion speed, viscosity and the hysteresis. Oxidation had an effect considerably on the wetting phenomena using the melting metal.(4) Inclined Plate and Parallel Plate Method. The static contact angle can be evaluated from tase methods but there were some difference with another research results.(5) Comparing the results of each methods. On the ground, the static contact angle values were almost same between growing drop method and Meniscograph method and the liquid bridge's result agree with the reducing contact angle for other method. Under microgravity, the static contact angle values became larger than another reducing contact angle values at the liquid bridge method. Less