Triangulation and Liquidus Surface in the Al2O3 -- ZrO2 -- La2O3 Phase Diagram

A projection has been constructed for the liquidus surface in the phase diagram for the Al^sub 2^O^sub 3^ -- ZrO^sub 2^ -- La^sub 2^O^sub 3^ system on to the plane of the concentration triangle. There are found to be two partially quasibinary sections LaAlO^sub 3^ -- (98.5 mole% ZrO^sub 2^ -- 1.5 mole% La^sub 2^O^sub 3^) and La^sub 2^O^sub 3^·11Al^sub 2^O^sub 3^ -- (98.5 mole% ZrO^sub 2^ -- 1.5 mole% La^sub 2^O^sub 3^) together with one quasibinary LaAlO^sub 3^ -- La^sub 2^Zr^sub 2^O^sub 7^ section, which triangulate the ternary system, and the phase diagrams have been constructed for them. There are nine fields of primary crystallization for phases based on the T and F forms of ZrO^sub 2^, the X, H, and A forms of La^sub 2^O^sub 3^, and also the phases La^sub 2^Zr^sub 2^O^sub 7^, LaAlO^sub 3^, La^sub 2^O^sub 3^·11Al^sub 2^O^sub 3^, and Al^sub 2^O^sub 3^, together with two quasibinary eutectics and three ternary ones. It is not found that there are any ternary phases and solid-solution regions based on the components and the binary compounds. The minimum temperature in the system is 1665°C. The interactions are basically of eutectic type.[PUBLICATION ABSTRACT]