Phase diagrams of the systems Al_2O_3-ZrO_2-Ln(Y)_2O_3 as a source of multiphase eutectics for creating composite structural and functional materials

摘要

Phase equilibria in the ternary systems Al_2O_3-ZrO_2-Ln(Y)_2O_3 (Ln = La, Nd, Sm, Gd, Er, Yb and Y) were investigated by identical methods in all range of concentrations and 1250-2700 °C temperature range using differential and derivative in solar furnace thermal analysis in controlled medias, X-ray diffraction phase analysis, local X-ray spectral analysis, chemical analysis, electron and optical microscopy, petrography. The phase diagrams of the systems studied are presented as isothermal at 1650 °C sections and melting diagrams. The interaction in the systems is characterized by the absence of ternary compounds and regions of appreciable solid solutions based on the binary compounds and components. Only narrow regions of ternary solid solutions were discovered at high temperatures by CALPHAD method and because of existing small solubility on the base of ZrO_2 in the binary bounding system Al_2O_3-ZrO_2.