Low thermal conductivity thermal barrier coating deposited by the solution plasma spray process

This work seeks to develop an innovative thermal barrier coating (TBC) that will exhibit low thermal conductivity and high durability compared with that of current TBCs. To achieve this objective, a multiple component co-doped zirconia chemistry was selected for the topcoat of the TBC system, and a new process – Solution Plasma Spray (SPS or SPPS) – was employed to produce desirable microstructural features: the co-doped zirconia TBC contains ultrafine splats, high volume porosity and vertical cracks, for lower thermal conductivity and better durability, respectively. Test results verified a low thermal conductivity of 0.55–0.66 W/K·m over a temperature range of R.T. to 1300 °C, 1/3X that of EB-PVD 8YSZ TBCs, and its thermal cycling durability was 2.5X that of APS 8YSZ TBCs and 1.5X that of EB-PVD 8YSZ TBCs.