Experimental investigation and thermodynamic calculation of phase equilibria in the ternary Si-Zn-Zr system

The phase equilibria of the Si-Zn-Zr ternary system at 450 °C and 600 °C were studied using the equilibrium alloy method. The phase constitution of the alloys were analyzed by means of the scanning electron microscope equipped with energy dispersive X-ray spectroscopy (SEM-EDS), and X-ray diffraction (XRD). The results show that eleven three-phase regions exist in the isothermal section at 450 °C, and twelve three-phase zones exist in the isothermal section at 600 °C. A ternary compound Zr 6 Zn 23 Si was found to exist in the isothermal section at 600 °C. The solubility of the third component in the binary compounds was determined. Combined with experimental results and literature data, the thermodynamic calculation of the Si-Zn-Zr ternary system was carried out using the CALPHAD (Calculation of Phase Diagrams) method. A set of self-consistent thermodynamic parameters for the Si-Zn-Zr ternary system was obtained. The calculated results are in good agreement with the experiment data. • Eleven tri-phase regions exist in the Si-Zn-Zr system at 450 °C. • Twelve tri-phase regions exist in the Si-Zn-Zr system at 600 °C. • The solubility of the third component in the binary compounds was determined. • A ternary compound Zr 6 Zn 23 Si was found to exist in the isothermal section at 600 °C. • A set of self-consistent thermodynamic parameters for the Si-Zn-Zr ternary system was obtained.