Wettability of pure metals with liquid sodium and liquid tin

Wettability of pure transition metals with liquid sodium or liquid tin has been evaluated using a contact angle droplet method. Titanium, iron, nickel, copper and molybdenum pure metals were selected as specimens in this experiment. All experiments were carried out in high purity argon gas and extremely low moisture to avoid influence of oxygen to liquid metal. Measurement temperature was set just above the melting temperature of each liquid metal. As a result, for both liquid sodium and liquid tin, the measured contact angle changed depending on the atomic number of substrate metals. An electronic structure of the interface between liquid metal and substrate metal was calculated by the molecular orbital method. Simple cluster models of the interface between liquid metal and substrate transition metals were used in this calculation. It was found that the calculation results well express an electronic state of interface. The atomic bonding between liquid metal atom and substrate metal atom changed depending on the kind of substrate metal. Also, the atomic bonding between substrate metal atoms changed similarly. It became clear that there was a reasonable relationship between an atomic bonding ratio and the contact angle. It clearly suggested the atomic bonding affected wettability between liquid metal and substrate metal. The atomic bonding was obtained as one of indications to reveal the wettability by transition metals with liquid metals. © 2021 The Japan Institute of Metals and Materials.