The Al2O3-ZrO2-Yb2O3 phase diagram. I. Isothermal sections at 1250 and 1650°C

Abstract

Isothermal sections at 1250 and 1650°C of the Al 2 O 3 -ZrO 2 -Yb 2 O 3 phase diagram are plotted for the first time. Phase equilibria are established at these temperatures. No ternary compounds and appreciable solid solution regions based on components or binary compounds are found in the ternary system. A partially pseudobinary section Yb 3 A 5 -F triangulating the Al 2 O 3 -ZrO 2 -Yb 2 O system is established.

Mass spectrometric study of thermodynamic properties in the Yb2O3‐ZrO2 system at high temperatures

“…According to calculations, the compound Yb 4 Zr 3 O 12 (δ‐phase) is stable up to 1914 K, consistent with previous results . Serious disagreement between the experimental phase equilibrium data obtained by Wang and Lakiza et al . concerning the composition of the C‐phase in equilibrium with the δ‐phase and in equilibrium with fluorite in the Yb 2 O 3 ‐ZrO 2 system were pointed out by Fabrichnaya and Seifert .…”

“…Wang indicated substantially higher solubility of ZrO 2 in the C‐phase than Lakiza et al . There are also discrepancies in the composition of the fluorite phase in equilibrium with the C‐phase between the data of Lakiza et al . and Stubican et al ., both indicating the lowest solubility of Yb 2 O 3 in fluorite, Wang indicating slightly higher Yb 2 O 3 solubility than other reports and Rouanet who indicated the highest solubility of Yb 2 O 3 in fluorite.…”

“…concerning the composition of the C‐phase in equilibrium with the δ‐phase and in equilibrium with fluorite in the Yb 2 O 3 ‐ZrO 2 system were pointed out by Fabrichnaya and Seifert . Wang indicated substantially higher solubility of ZrO 2 in the C‐phase than Lakiza et al . There are also discrepancies in the composition of the fluorite phase in equilibrium with the C‐phase between the data of Lakiza et al .…”

Al2O3-ZrO2-Yb2O3 phase diagram. II. Liquidus surface

“…Binary bounding systems have been sufficiently examined, their phase diagrams have been plotted [1-13]. The paper [15] represents experimental isothermal sections of the Al 2 O 3 -ZrO 2 -Yb 2 O 3 phase diagram at 1250 and 1650°C and reveals conditionally quasibinary Yb 3 Al 5 O 12 (Yb 3 A 5 )-F section, where F is a solid solution of 28 mol.% Yb 2 O 3 in ZrO 2 . No new phases or noticeable regions of ternary solid solutions based on binary compounds or components have been revealed in the system.…”

“…1 show the compositions of the alloys examined. The numeration corresponds to that in the table from [15]. In determining coordinates of the ternary eutectics, the composition of additional alloys was selected using the method of successive approximations.…”