Thermodynamics of homogeneous crystal nucleation in Al-RE metallic glasses

In the present paper, thermodynamic data of the Al-Ce and the Al-Nd systems are analysed by a new CALPHAD assessment, in which special emphasis is put on the description of the short range order in the undercooled liquid. A reliable description of the thermodynamics of the undercooled liquid and the amorphous phase can only be achieved by considering thermodynamic data of each metastable state. The results demonstrate a stabilization of the liquid phase on undercooling up to the glass transition temperature. The thermodynamic properties of intermetallic compounds are also reassessed. From the calculated Gibbs energies, the driving force for nucleation of primary fcc-Al and Al11RE3 crystals from the AI-rich liquid and amorphous phase have been computed as a function of temperature.