The Al2O3–HfO2–Y2O3 phase diagram. IV. Vertical sections

Abstract

For better presentation of the Al2O3–HfO2–Y2O3 phase diagram over wide ranges of temperatures and concentrations, three vertical sections are plotted to show interactions in the ternary system. The Y2O3 bisector shows the Y2O3-rich region of the Al2O3–HfO2–Y2O3 phase diagram and explains the mechanism of X ⇆ H ⇆ A ⇆ B phase transformations for Y2O3 solid solutions. The 10 mol.% HfO2 (10H) isopleth shows the Al2O3–HfO2–Y2O3 structure in the region adjacent to the Al2O3–Y2O3 binary bounding system. The HfO2 bisector shows the structure of the HfO2-rich region and the mechanism of F ⇆ T ⇆ M phase transformations for HfO2 solid solutions.