Effect of a Slight Amount of Dissolved Oxygen on the Surface Tension of Liquid Copper

Abstract

The effect of a slight amount of dissolved oxygen below 0.02 at% on the surface tension of liquid copper has been carefully measured by the sessile drop method at 1373, 1473, 1573 and 1673 K. The surface tension of liquid copper over the region of dilute oxygen concentrations decreased with increasing partial pressure of oxygen in the atmosphere, and this tendency was remarkable at lower temperatures. The temperature coefficient of surface tension of liquid copper changed from negative to positive with increasing oxygen content. It can therefore be presumed that the results reported by Krause and by Pugachevich et al., in which the surface tension of liquid copper increases with increasing temperature, may be caused by the presence of a slight amount of oxygen in the atmosphere or specimen.