2022 年 61 巻 1 号 p. 135-139
The effect of temperature and phosphorus addition on the surface tension of molten Cu-P alloys were measured by the oscillating droplet method using the electromagnetic levitation technique. We successfully measured the accurate surface tension of molten samples that were sufficiently above the liquidus temperature. The surface tension of liquid copper was determined in its pure state, which is free from any contamination, such as oxygen adsorption and chemical reaction with the supporting material. The surface tension of the molten sample was decreased as phosphorus addition was increased. The surface tension of molten Cu-P alloys was well expressed as functions of temperature and of phosphorus activity from the measurement results using the Szyszkowski model. Furthermore, the enthalpy and entropy change in phosphorus adsorption on liquid copper were also estimated.
