Density, Surface Tension, and Properties of Nickel–Oxygen Melts

Abstract

The structural and physicochemical properties (density and surface tension parameters) of the nickel melt containing a detrimental impurity (oxygen) in an amount of 0.01, 0.02, and 0.03 wt % of the pure nickel content are studied. The temperature dependences of the density of melts of the Ni–O system are characterized by higher values relative to the pure solvent and compression effect formation. Oxygen in the nickel melts possesses a high surface activity and also affects an increase in the surface tension under the heating conditions. The amount of oxygen adsorbed on the surface depends on the temperature and melting conditions. Under the heating and cooling conditions, the amount of the adsorbed substance at low temperatures is approximately twofold higher than that at high temperatures. In a content range of 0.018 wt % oxygen, the surface tension isotherms contain a minimum, the adsorption isotherms contain a maximum, and the density isotherms exhibit inflection points of the function. The appearance of specific points in the curves of the structure-sensitive properties makes it possible to predict the possibility of a structural transition caused by the decomposition of an oxygen-saturated γ-like liquid solution to a γ solution and microgroups of NiO oxide.