Abstract
In this work, one new technique named as supersonic suspension plasma spraying (SSPS) is applied to deposit quasi-columnar scandia-yttria co-doped zirconia (ScYSZ) and yttria-stabilized zirconia (YSZ) thermal barrier coatings (TBCs). The phase composition, microstructural evolution, fracture toughness and failure behavior of both TBCs before and after thermal cycling tests at 1300 °C were systematically studied. It was found that both as-sprayed TBCs were fully non-transformable tetragonal (t’) phase. After the thermal cycling test, tetragonal (t) phase and cubic (c) phase formed for the SSPS-YSZ TBC, while single t’ phase retained for the SSPS-ScYSZ coating. The fracture toughness of the ScYSZ coating was comparable or superior to that of the YSZ coating. As for the thermal cycling behavior, the lifetime of the ScYSZ coating was better than that of the YSZ coating, which confirmed that ScYSZ was a promising alternative material for YSZ.
