Thermodynamic Properties of Iron Melts with Titanium, Zirconium, and Hafnium

Abstract

The literature data on the enthalpy of mixing and thermodynamic activity of liquid alloys of Fe–Ti, Fe–Zr and Fe–Hf are summarized. It is shown that the thermodynamic properties of these systems are characterized by significant negative deviations from the ideal behavior. In the framework of the associated solution model were described the concentration and temperature dependences of the thermodynamic functions of mixing of Fe–Ti, Fe–Zr and Fe–Hf systems. For the temperature dependence of the thermodynamic properties of the considered systems are characteristic an increase of negative deviations from the ideality with decreasing temperature and increasing thermodynamic stability of supercooled melts. Analysis of the degree of short-range order in the system melts, estimated as the total mole fraction of associates Σx_ass at the glass transition temperature, allows us successfully interpret the known concentration ranges of amorphization melt Fe–Zr and Fe–Hf systems and perform the forecast of composition range of amorphization for molten Fe–Ti system.