Abstract

As operating temperatures of engines or turbines continually increase for higher efficiency, significant amounts of researches have been focused on finding new materials, which would be alternatives to conventional yttria-stabilized zirconia (YSZ) for thermal barrier coatings (TBCs). In this study, phase evolution and thermo-physical properties of La_2(Zr_1-xHf_x)_2O_7 pyrochlore systems are investigated for TBC applications. La_2(Zr_1-xHf_x)_2O_7 systems are comprised by selecting La3+ as A-site ions and Zr4+/Hf4+ as B-site ions in A_2B_2O_7 pyrochlore structures. For the developed phases in La_2(Zr_1-xHf_x)_2O_7 compositions, thermo-physical properties such as thermal conductivity, thermal expansion coefficient are examined. The potential of these La_2(Zr_1-xHf_x)_2O_7 compositions for TBC application is also discussed.

• Keywords: Thermal barrier coatings;Rare-earth oxides;Pyrochlore;Thermo-physical properties;