Experimental investigation and thermodynamic modeling of the Zr-Y system

Abstract

Based on the critical review of all the available experimental data in the literature, 8 key alloys were prepared by arc melting to investigate the phase equilibria in the Zr-Y system, These alloys, which were annealed at 5 different temperatures (800 °C, 1000 °C, 1100 °C, 1120 °C, 1160 °C), were analyzed by means of X-ray diffraction, differential scanning calorimetry, optical microscopy and scanning electron microscopy with energy-dispersive X-ray spectroscopy. The results showed that a peritectoid reaction (βZr) + (αY) = (αZr) occurs at 886 °C ± 5 °C, and an eutectic reaction L = (βZr) + (αY) occurs at 1313 °C ± 5 °C. Taking into account the experimental data obtained both from this work and the literature, the Zr-Y system was thermodynamically modeled. The previously reported temperature for the peritectic reaction of (βY) + L = (αY) at about 1490 °C is supported by our thermodynamic calculation. Comparison between the calculated and measured phase diagrams shows that the thermodynamic calculation can well account for the experimental data.