Composition Effects of La2Ce2O7 Thermal Barrier Coatings Against Calcium-Magnesium-Aluminum-Silicate (CMAS) at 1250 °C
Composition Effects of La2Ce2O7 Thermal Barrier Coatings Against Calcium-Magnesium-Aluminum-Silicate (CMAS) at 1250 °C
Wednesday, May 13, 2015
Exhibit Halls A&B (Long Beach Convention and Entertainment Center)
The evaporation of both CeO2 and La2O3 in high temperature plasma arc leads to deviation of plasma sprayed La2Ce2O7 coating composition from the starting powder particle. Such change results in significantly inhomogeneity of compositions within a coating which influences the performance of calcium-magnesium-silicate (CMAS) corrosion. In this study, splats with different Ce/La ratio were obtained by plasma sprayed La2Ce2O7 powders. The compositions of splats were characterized by scanning electron microscopy and energy dispersive spectrum (EDS), and splat dimensions were characterized by 3D laser microscopy. The phase structure of splats exposed at high temperature for different durations was characterized by X-ray diffraction. The effect of splats of different Ce/La ratio on the CMAS corrosion after thermal exposure at 1250°C for different durations was investigated.