Thermal Properties and Phase Transformation Behavior of YSZ Co-Doped by Rare Earth Oxides (La2O3, Gd2O3, Yb2O3)

Thermal barrier coating (TBC) materials were used to the application at high operating temperature component of gas turbine engines. Recently, 6-8 wt.% yttria-stabilized zirconia (8YSZ) has been widely used material for TBC. However, 8YSZ deteriorates at temperatures above 1200 °C due to their sintering phenomena and phase transition, which limiting its use as the TBC material for high temperature gas turbine. Co-doped YSZ powders containing rare earth oxides have recently been the subject of ongoing research. So, we recommend improved three types of YSZ compositions co-doped with La, Gd, and Yb. The YSZ co-doped with the compositions were prepared by ball milling and then made pellets and sintered. Then, we analyzed microstructure, thermal properties, mechanical properties and phase transformation behavior with various tools. The addition of La, Gd and Yb into YSZ effectively make thermal conductivity low and improve phase stability and mechanical properties of the YSZ which would improve the performances of thermal barrier coating. Therefore, we suggest that three types of compositions can be used instead of 8YSZ as materials for next-generation gas turbine engines.