Contact Angles between Liquid Bismuth and Pure Iron and Mild Steel. A Study of Interfacial Reactions

The receding and advancing contact angles between liquid bismuth and pure iron and mild steel have been measured and the change of contact angle with time at a series of temperatures has been determined. Two chemical reactions have been found to take place at the solid-liquid interface. The first is thought to be the reaction of chloride ions (present as bismuth oxychloride impurity in the solution) with the iron surface; the second the reduction of bismuthyl ions by the iron. The first process has an activation energy of 30 kcal and the second process an activation energy of 15 kcal.