Hot Corrosion Behavior of La2Ce2O7-Based Plasma-Sprayed Coating

Abstract La 2 Ce 2 O 7 (LC) has been identified as a promising thermal barrier coating (TBC) for use up to 1250 °C. In this study, a TBC system was deposited on grit-blasted Inconel 738 using atmospheric plasma spraying (APS) with NiCrAlY as the bond coat, followed by YSZ, and then LC as the top layer. The coatings were exposed to a mixture of molten Na 2 SO 4 (45 wt.%) and V 2 O 5 (55 wt.%) at 950 °C for hot corrosion. On the top LC layer, LaVO 4 , CeVO 4 and CeO (1.66–2.00) formed as hot corrosion products after 4 h exposure. A reaction between YSZ and the corrosion products could not be observed due to the absence of YVO 4 . The hot corrosion mechanism of the LC-based TBC is also discussed in this study.