Experimental investigation of phase equilibria in the Ni–Fe–Zr ternary system

Abstract

Three isothermal sections of the Ni–Fe–Zr ternary system at 1000, 1100, and 1200 °C were experimentally determined using equilibrated ternary alloys. No ternary compound is found in this system. The obtained experimental results show that among three isothermal sections, the (γFe, Ni) phase region extends from the Ni-rich corner to the Fe-rich corner, and the solubility of Zr in the (γFe, Ni) phase is small. The phase equilibrium at 1100 °C is similar to that at 1000 °C. The Ni₅Zr, Ni₁₀Zr₇, and Fe₂Zr phases have solid solution composition ranges, but the Ni₇Zr₂, Ni₂₁Zr₈, NiZr, NiZr₂, and Fe₂₃Zr₆ phases almost exhibit nearly linear compounds both at 1000 and 1100 °C. The solubilities of Fe in Ni₇Zr₂ phase and Ni in Fe₂Zr phase are extremely large. At 1200 °C, the liquid phase of Zr-rich corner forms the continuous region from the Ni–Zr side to the Fe–Zr side. Additionally, the solubilities of Fe in Ni₅Zr, NiZr phases and Ni in Fe₂₃Zr₆ phase clearly increase with increasing temperature to 1200 °C. The obtained results may provide a better understanding of microstructures and further development of the Ni–Fe–Zr alloys.