The stabilization of zirconium dioxide in the ternary system CaO-TiO 2-ZrO 2

Abstract

The subsolidus diagram of the ternary system CaO-TiO 2-ZrO 2 has been determined, then used for the study of the stabilization of zirconium dioxide. It has been found that only three of the eight elementary ternary subsystems are suitable for stabilization: ZrO 2-CaO.ZrO 2-CaO.TiO 2, ZrO 2-CaO.TiO 2-CaO.ZrO 2.2TiO 2 and ZrO 2-ZrO 2.TiO 2-CaO.ZrO 2.2TiO 2. The phase composition at thermodynamic equilibrium has been determined for twelve compositions in these three subsystems. The phases have been determined by X-ray diffraction on samples fired at temperatures in the range 1350–1450 δC. It has been found that, for full stabilization of zirconium dioxide, at temperatures under 1450 °C, it is necessary to choose compositions in the elementary ternary subsystem ZrO 2-CaO.ZrO 2-CaO.TiO 2. The cubic variety of the resulting zirconium dioxide is characterized by a = 5.10 A ̊ .