Effects of Oxygen and Temperature on the Surface Tension of Liquid Iron and Its Wettability of Alumina

The surface tension and the contact angle of liquid iron on the alumina substrate were measured at 1873 K, 1923 K, 1973 K and 2023 K by the sessile drop method.The surface tension of liquid iron decreases with increasing oxygen concentration in the iron over the temperature range from 1873 K to 2023 K.The temperature coefficient of surface tension is negative for the lower oxygen concentration than 0.007 mass%, but it is positive for the higher oxygen level.The standard free energy change for the adsorption reaction of oxygen at the liquid iron surface is given by the following equation:(This article is not displayable. Please see full text pdf.) The contact angle of liquid iron on the alumina substrate decreases and the work of adhesion increases with increasing oxygen concentration in the iron. However, the contact angle is not affected by the temperature.