THERMODYNAMIC ANALYSIS OF INTERACTION PROCESSES IN THE Cu-Zr-O SYSTEM REALIZED IN LIQUID COPPER MELT
Thermodynamic modeling of interaction processes of zirconium and oxygen dissolved in liquid copper melt was done. It was found that the components of Cu 2O-ZrO 2 system are conjugated with liquid metal melt in Cu-Zr-O system. The coordinates of a liquidus line of the Cu 2O-ZrO 2 diagram were determined using the mel¬ting temperature data and the heat of fusion data about Cu 2O and ZrO 2 oxides as well as the theory of perfect ionic solutions and subregular ionic solutions. The calculations of activities of Cu 2O and ZrO 2 in the oxide melt showed that and have negative deviation from Raoult’s law in the range of oxide melts existence. The surface of component solubility in metals melts (SCSM) of Cu-Zr-O system was constructed for the temperature range from 1100 to 1300 °С. The temperature dependence of the interaction parameter of liquid copper was determined during SCSM thermodynamic modeling. The compositions of metals melt in equilibrium with pure solid Cu 2O and ZrO 2 oxides and in equilibrium with oxides melt were determined. The lines of three-phase equilibria (“liquid metal - oxide melt - pure solid Cu 2O oxide”; “liquid metal - oxide melt - pure solid ZrO 2 oxide”; “liquid metal - pure solid Cu 2O oxide - pure solid ZrO 2 oxide”) were calculated. The point of the four-phase equilibrium “liquid metal - oxide melt - pure solid Cu 2O oxide - pure solid ZrO 2 oxide” was set. The isotherms of oxygen solubility in liquid copper were plotted in the SCSM. The maximum of the deoxi¬dizing ability of zirconium in liquid copper was defined. High deoxidizing ability of zirconium in liquid copper melt was defined.