The Properties of Solution Precursor Plasma Spray Nanostructured Thermal Barrier Coatings

About 300 μm thickness uniform thermal barrier coatings (TBCs) were deposited on the 1Cr18Ni9Ti samples by solution precursor plasma spray (SPPS). The analysis methods, such as TEM, SEM, and XRD were used to characterize the coatings in the aspects of microstructure and phase compositions. The samples were quenched from 1121 °C to room temperature by forced-air to measure the thermal cycling capability. Coatings density were measured by means of water displacement. The experimental results show that grain size of the SPPS TBCs is about 30 nm with desired tetragonal phase ZrO2, and the SPPS TBCs(with 16% porosity) consist of arcuate pores, gelatin and melted particles. The hardness of the coatings is HR45Y38.5 and bond strength between coatings and substrates is 24.2 MPa. The thermal shock test show the coatings have a average life of 500 cycles which is about 2.5 times than that of conventional air plasma spray (APS) TBCs.