Study of the microstructural control of Ba(Mg1/3Ta2/3)O3 perovskite thermal barrier coating deposited by solution precursor plasma spray

Vertical grain and columnar structured Ba(Mg1/3Ta2/3)O3 thermal barrier coating deposited by solution precursor plasma spray

“…Considering its high melting temperature, this paper proposes a new application for BMT, namely applying BMT as a thermal insulation coating material for niobium alloy, which is recognized as the next-generation structural material for aerospace and a substitute for nickel alloy at higher temperatures [27]. Referring to the results obtained in previous work [26], three representative parameters related to precursor feed rate and atomization, spraying distance and surface roughness are chosen to deposit BMT on niobium alloy and to assess feasibility.…”

“…The main parameters of APS and Mo(Si, Al)2 feedstock preparation were described in previous work [29]. After the bond coat deposition, abrasive paper (180 grit) was used to smooth the coating surface, which was proven to later reduce the topcoat intercolumnar gaps [26]. The samples were then cleaned using acetone and ethanol, in an ultrasonic bath.…”

“…The surface roughness of the coating was measured with a Surftest SJ-210 (Mitutoyo, Japan). The coatings' porosity was calculated with the open source software ImageJ (National Institutes of Health, USA), for which the algorithm was described in previous work [26].…”

“…Finally, instead of adopting 45-125 μm powder BMT as feedstock in APS [25], RF SPPS feeds solution precursors directly into the core of the plasma jet to fabricate advanced coatings with unique microstructural feature [26].…”

“…Following our previous reports on BMT deposition by means of RF ICP, where precursors and spraying parameters have been optimized for phase and microstructural control [20,26], this paper presents a new BMT coating microstructure deposited by RF SPPS. The vertical grains of this structure are distinct features that depart from the ones obtained by DC SPS/SPPS and EB-PVD processes.…”