Al₂O₃–ZrO₂–Yb₂O₃ Phase Diagram.
III. Solidus Surface and Phase Equilibria in Alloy Solidification

Abstract

The solidus surface for the Al₂O₃–ZrO₂–Yb₂O₃ phase diagram is plotted onto the concentration triangle for the first time. It consists of four isothermal three-phase fields that correspond to two invariant eutectic equilibria and two invariant peritectic equilibria. The solidus surface also includes five ruled surfaces representing the end of crystallization in binary eutectics. The highest solidus temperature in the system is 2710 °C, which is the melting temperature for pure ZrO₂, while the lowest temperature is 1765 °C, which is the melting temperature for the AL+F+Yb₃A₅ ternary eutectic. No ternary compounds or noticeable areas of solid solutions based on components and binary compounds are found in the ternary system. The phase equilibrium diagram and reaction scheme for the equilibrium crystallization of Al₂O₃–ZrO₂–Yb₂O₃ alloys are plotted using data on bounding binary systems and liquidus and solidus surfaces.