Synthesis and characterization of nanostructured t′-YSZ spherical feedstocks for atmospheric plasma spraying

The properties of feedstocks have a significant effect on the quality of as-sprayed coatings. The 8YSZ feedstocks have been widely used in atmospheric plasma spraying (APS) for the preparation of thermal barrier coatings (TBCs). In this paper, the nanostructured APS 8YSZ spherical feedstocks were successfully synthesized by the nanopowder granulation method. The microstructures and physical properties of as-prepared 8YSZ feedstocks were characterized. By contrast, the phase composition of conventional 8YSZ feedstocks was also analysed. The results show that the nanostructured spherical 8YSZ feedstocks with the median particle size (d50) of 33.22 μm whose grain size is about 20 nm consist of the non-transformable tetragonal (t′) phase and no other phases. Furthermore, the density of the as-prepared feedstocks is high enough and the nanostructured 8YSZ feedstocks are free-flowing. The nanostructured t′-YSZ feedstocks have excellent combination properties, which makes them have a broader application prospect in APS TBCs compared with the conventional 8YSZ feedstocks in future.