La2(Zr0.7Ce0.3)2O7 thermal barrier coatings prepared by electron beam-physical vapor deposition that are resistant to high temperature attack by molten silicate

Calcium-magnesium-alumino-silicate (CMAS) attack is a significant failure mechanism for thermal barrier coatings (TBC). In this study, La-2(Zr0.7Ce0.3)(2)O-7 (LZ7C3) TBC prepared by electron-beam physical vapor deposition was found to be highly effective in resisting CMAS infiltration for prolonged durations (24 h, 1250 degrees C), while conventional Y2O3-stabilized ZrO2 TBC was completely penetrated by molten CMAS within 30 min. This resistance was achieved through crystallization of CMAS as a result of high temperature chemical interactions between LZ7C3 coating and CMAS glass. The crystalline products, mainly consisted of La-Ce apatite and C-ZrO2, tended to form a sealing layer and can effectively prevent CMAS from further infiltration. (C) 2016 Elsevier Ltd. All rights reserved.