Improved thermal fatigue resistance in thermal barrier coatings via suspension plasma spray technique

The thermal cycle fatigue behavior of a suspension plasma-sprayed thermal barrier coating (SPS-TBC) with cauliflower-like columnar microstructure was investigated. The damage behavior of SPS-TBC was investigated compared with a conventional atmospheric plasma-sprayed (APS-) TBC. The thermally grown oxide (TGO) grew at the interface between the top- and bond-coats during not only the isothermal oxidation but also the thermal cycle fatigue. In the SPS-TBC, the growth of mixed oxide-type TGO can be suppressed. Additionally, the columnar structure of the SPS-TBC can prevent the propagation of delam-ination crack from the specimen edge promoted by thermal cycles. These results suggested that the SPS-TBC had superior thermal fatigue resistance because of its columnar structure. (C) 2020 Elsevier B.V. All rights reserved.