Projections of the Liquidus and Solidus Surfaces of the Al₂O₃–HfO₂–Gd₂O₃ Phase Diagram

Abstract

Phase equilibria during crystallization of alloys in the Al₂O₃–HfO₂–Gd₂O₃ system are studied for the first time by physicochemical methods. Liquidus and solidus projections on the concentration triangle as well as the melting diagram and crystallization scheme are constructed. No new ternary compounds and appreciable ternary solid solution areas are found in the system. The maximum temperature in the system is 2820 °C and corresponds to the three-phase eutectic AL + F + GA (Е₃). Since crystallization in the system finishes by eutectic reactions, it allows materials of the quasiternary system to have the unique properties of HfO₂-based Т- and F-solid solutions in combination with properties of its other phases as composite materials.