Thermal stability and sintering behavior of plasma sprayed nanostructured 7YSZ, 15YSZ and 5.5SYSZ coatings at elevated temperatures

Nanostructured scandia, yttria doped zirconia (5.5SYSZ), 7 wt% yttria stabilized zirconia (7YSZ) and 15YSZ thermal barrier coatings (TBCs) were produced by plasma spraying on nickel-based superalloy substrates with NiCrAlY as the bond coat. The thermal stability and sintering behavior of the three as-sprayed TBCs at 1480 °C were investigated. The results indicated that the thermal stability of SYSZ and TBCs was longer than the 7YSZ TBCs due to higher amount of tetragonal phase. Furthermore, the results demonstrated that the nanostructured 7YSZ coating exhibits higher sintering resistance than 5.5SYSZ TBC.