Thermal and mechanical properties of Sc2O3-CeO2 co-stabilized zirconia ceramic as promising thermal barrier coating material

CeO2 and Sc2O3 co-stabilized ZrO2 ceramics have attracted much attention as potential thermal barrier coatings (TBCs) materials for applications above 1300 degrees C. In this study, a series of Sc0.04CexZr0.96-xO1.98 (SCZ, x = 0.08, 0.10, 0.12, 0.16) ceramic materials were synthesized with the solid-state method and their phase stability, microstructures and thermo-physical properties were systemically investigated by x-ray diffraction (XRD), Raman spectra, field emission scanning electron microscopy (SEM), thermal dilatometer, laser flash apparatus (LFA), and Vickers hardness tester. The results showed that Sc0.04Ce0.12Zr0.84O1.98 (4S12CZ) and Sc0.04Ce0.16Zr0.80O1.98 (4S16CZ) ceramic materials still maintained stable tetragonal phase structure after 100 h high temperature treatment at 1500 degrees C. SCZ had a high thermal expansion coefficient (TEC), low thermal conductivity, and high fracture toughness. The TEC of the ceramics increased with CeO2 addition because lattice energy reduced with increasing substitution of Zr4+ by bigger Ce4+ while thermal conductivity decreased due to the increase of lattice distortion. Compared with 4S12CZ, 4S16CZ exhibited a higher fracture toughness of 6.48 +/- 0.04 MPa m(1/2) and showed the better anti-sintering property. Besides, the thermal conductivity, TEC and thermal cycling lifetime of 4S16CZ were optimal. The comprehensive performance of 4S16CZ suggested it could be explored as a promising TBC material for high-temperature application.

Automated summary

CeO2 and Sc2O3 co-stabilized ZrO2 ceramics have been studied for their potential application as thermal barrier coatings materials above 1300 degrees C. The Sc0.04Ce0.16Zr0.80O1.98 (4S16CZ) ceramic material showed superior performance in stability and thermal properties in high-temperature environments, suggesting its potential as a promising TBC material.