Computer Simulation of Time Dependent Wetting Behavior in the Wetting Balance

초록

Wetting balance test is known to be the most versatile method for wettability evaluation, because it can provide quantitative information and time dependent wetting behavior. There exist numbers of studies related with the wetting force, however, as to wetting time, there is no theoretical backgrounds nor mathematical analysis; only experimental deduction exists. In this study, the wetting time is focused as a wettability index. The wetting curve which shows time dependent wetting behavior is predicted using computer simulation. The mechanism of meniscus rise is analyzed. As a result, a good agreement between calculated and measured wetting curve can be obtained. It is found that the roughness of the sample and viscosity of a liquid are the major variables that determine the wetting time and wetting rate. Results of wetting balance using Sn-Ag solder are different with those of predicted. It is proposed that heat transfer, formation of intermetallic compounds and oxide layer on the liquid surface are the major problem for this mismatch.