Gradient La_2Ce_2O_7/YSZ thermal barrier coatings tailored by synchronous dual powder feeding system

摘要

Progress in the design and fabrication of thermal barrier coating (TBC) is strongly dependent on the application of new materials and deposition methods. In this work, one novel and efficient plasma spraying method was employed to deposit a La2Ce2O7 (LC)/YSZ gradient TBC using a synchronous dual powder feeding system, in which the melting state and feeding rate of LC or YSZ feedstock powder can be precisely controlled. The experimental and simulation results suggested that the as-sprayed LC/YSZ TBC presented an obvious gradient change along the coating thickness direction. The heat insulation temperature and thermal cycling property of gradient TBC were greatly improved compared to its double-layer-structured counterpart due to the increased interfaces and deflection of fatigue cracks resulted from the gradient structure. (C) 2018 Elsevier B.V. All rights reserved.