To protect the high-temperature components of gas turbines, 6–8 wt.% yttria stabilised zirconia (YSZ) has been extensively used as a thermal barrier coating (TBC) material. However, its application is severely limited at high temperatures because of zirconia phase transition and sintering densification above 1200 °C. This study developed modified YSZ with enhanced high-temperature thermal properties owing to the addition of various rare-earth doping elements. Among the various rare earth-doped compositions, all the thermal properties were significantly improved in compositions containing scandium, gadolinium, and dysprosium. Furthermore, in the selected compositions, the high-temperature thermal properties were analysed under heat treatment conditions of 1300 °C, with a target turbine inlet temperature (TIT) of 1500 °C. The high-temperature phase stability of the tetragonal phase was significantly improved in the newly developed compositions, and they exhibited glass-like low thermal conductivity (∼0.984 W/mK) due to the influence of lattice distortion caused by the differences in the substituent-ion mass and size, and the oxygen vacancies. Moreover, there was notable improvement in the thermal expansion coefficient (∼11 × 10−6/K) and resistance to high-temperature densification.
Bibliographical noteFunding Information:
This work was supported by the Industrial Strategic Technology Development Program of the Ministry of Trade, Industry and Energy ( MOTIE ) [grant number #20009895].
- High-temperature thermal property
- Modified YSZ
- Thermal barrier coatings
- Thermal conductivity
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Process Chemistry and Technology
- Surfaces, Coatings and Films
- Materials Chemistry