Abstract
For measuring the wetting of ceramics by liquid metals by the Meniscograph, at first we examined the wetting of copper by liquid mercury at 353 K∼383 K. It has become clear that there are three stages in the wetting process. The first stage is the onset of wetting and is related to the process of wetting. The second stage is the period of equilibrium for the initial wetting in a period of 10 s∼100 s after dipping. The third stage is the wetting accompanied by a chemical reaction between Cu/Hg, where the value of adhesion tension varies with time. The values obtained from many previous studies about the wetting were observed in this stage.
To determine the wetting speed, a model was introduced. In this model, the samples were dipped into Hg at a high speed to avoid the wetting of the samples by Hg during the dipping. The surface tension of Hg, γlv, acts on the samples at t=0, then the wetting starts and proceeds with time exponentially. According to this model, the wetting speed is given by the following equation:
γlvcosθ=−(γlv+C)exp(kt)+C
C: equilibrium adhesion tension
k: constant of wetting speed
t: time after dipping
