微重力环境下的表面张力及无接触测量

Comprehension and Non-contact Measurement of Surface Tension Under Microgravity

表面张力是材料重要的物理化学参数之一,尤其在微重力条件下,由表面张力引起的科学现象一直备受关注.静滴法是地面重力条件下进行熔体表面张力测量的主要方法,该方法的测量结果精确,但在微重力环境下该法应用尚存在一些问题.本文基于对表面张力理论的思考,阐述了对其测量方法的认识和见解,并讨论了地面上采用静滴法对熔体的表面张力进行测量研究以及静滴法在微重力条件下应用的困难.进而介绍了利用悬浮技术进行熔体表面张力测量的无接触测量方法,特别介绍了电磁悬浮法,该法避免了由于容器接触带入杂质所引起的误差,尤其在微重力条件下消除了重力的影响,测量精度得到显著提高.

Surface tension is one of the most important physical chemistry parameters in material field. Many interface phenomena under microgravity attract scientists and need farther study. Sessile drop method is the main way to measure surface tension of melts, which works well on the earth. However, it is difficult to be used under microgravity environment. The paper expresses new cognition about measurement after thinking of the theory of surface tension, and discusses the difficulty of using sessile drop method under microgravity environment. This paper introduces levitation method to measure the surface tension, especially the electromagnetic levitation method, which avoids the error brought by vessel contacting. Under microgravity environment, the electromagnetic levitation method can improve the measurement precision.