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 <sub>2</sub>O-ZrO <sub>2</sub> system are conjugated with liquid metal melt in Cu-Zr-O system. The coordinates of a liquidus line of the Cu <sub>2</sub>O-ZrO <sub>2</sub> diagram were determined using the mel¬ting temperature data and the heat of fusion data about Cu <sub>2</sub>O and ZrO <sub>2</sub> oxides as well as the theory of perfect ionic solutions and subregular ionic solutions. The calculations of activities of Cu <sub>2</sub>O and ZrO <sub>2</sub> 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 <sub>2</sub>O and ZrO <sub>2</sub> oxides and in equilibrium with oxides melt were determined. The lines of three-phase equilibria (“liquid metal - oxide melt - pure solid Cu <sub>2</sub>O oxide”; “liquid metal - oxide melt - pure solid ZrO <sub>2</sub> oxide”; “liquid metal - pure solid Cu <sub>2</sub>O oxide - pure solid ZrO <sub>2</sub> oxide”) were calculated. The point of the four-phase equilibrium “liquid metal - oxide melt - pure solid Cu <sub>2</sub>O oxide - pure solid ZrO <sub>2</sub> 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.