Phase Diagrams of Refractory Oxide Systems and Microstructural Design of Materials

Abstract

It is shown that phase diagrams of refractory oxide systems based on ZrO₂, HfO₂, Al₂O₃, and rare earth oxides form the basis for microstructural design of various high-performance materials. Processing steps to produce coarse-grain ceramics in the HfO₂–ZrO₂–Y₂O₃, ZrO₂–Y₂O₃–Sc₂O₃, HfO₂–ZrO₂–Sc₂O₃, Y₂O₂–Er₂O₃, Y₂O₃–ZrO₂, Y₂O₃–HfO₂, Y₂O₃–Al₂O₃, Y₂O₃–SiO₂,and Y₂O₃–La₂O₃, systems to perform at temperatures up to 2200 °С are designed. Processing steps to produce high-performance fine-grain composites in the HfO₂–ZrO₂–Y₂O₃(Ln₂O₃)(Ln — Dy, Ho, Er, Tm, Yb), ZrO₂–Y₂O₃–Sc₂O₃, ZrO₂–Y₂O₃–Sc₂O₃, Al₂O₃–Zr(Hf)O₂–Ln(Y)₂O₃ (Ln — La, Nd, Sm, Gd, Er, Yb) and ZrO₂–Y₂O₃–CeO₂–Al₂O₃ systems are designed as well.