Measurement of dynamic surface tension of liquid metals using capillary jet method

Surface tension of liquid metal is sensitive to surface oxidation and it varies temporary in oxic condition. The temporally varing surface tension, i.e. dynamic surface tension, has great impact on many industrial processes relating to liquid metal. In this study, a novel and simple method for the dynamic surface tension of the liquid metals tension is proposed. This method determined the dynamic surface tension on the basis of the profile of a falling capillary jet, which is ejected horizontally. The dynamic surface tension for Wood's metal reaches equilibrium state from a initial value after gradual decreases or increase depending on oxygen concentration. The decrease of surface tension is caused by oxygen adsorption at relatively low oxygen concentration, and high oxygen concentration leads to the increase of surface tension by segregation. The relaxation time of the dynamic surface tension is the order of 10ms, and the dependency of the relaxation time on oxygen concentration can be also iterpreted as the result of oxygen adsorption and segregation.