Investigation of the Physicochemical Properties of Ceramics in the Sm2O3-Y2O3-HfO(2)System for Developing Promising Thermal Barrier Coatings

摘要

The effect of components of ceramics in the Sm2O3-Y2O3-HfO(2)system on their thermophysical properties was studied. It was shown that the most stable materials at 1400 degrees C are ternary ceramics in the system under investigation that contain <= 12.5 mol % Sm2O3; the thermal conductivity of these materials does not exceed 1.3 W/(m K). Increasing samarium oxide content in samples in the Sm2O3-Y2O3-HfO(2)system was found to lead to significant changes in phase equilibria at temperatures >= 1000 degrees C. The effect of the contents of individual components of the studied ceramics on the thermal conductivity and the linear thermal expansion coefficient, which largely determine the suitability of a ceramic material for using in a thermal barrier coating. It was shown that the addition to 12.5 mol % samarium oxide ensures the stability of the linear thermal expansion coefficient at acceptable values of the thermal conductivity of 0.8-1.6 W/(m K).