The corrosion behaviors of thermal barrier material of M-YTaO4 attacked by CMAS at 1250 °C

Abstract

The corrosion of YSZ TBCs attacked by calcium–magnesium–aluminosilicate (CMAS) is a serious problem. Yttrium tantalite (YTaO4), a new kind of potential thermal barrier ceramic material, was expected to replace the YSZ to manufacture the TBCs because of its great thermophysical characteristics. In this study, porous YTaO4 ceramic pellets, instead of actual TBCs, were used to investigate the CMAS corrosion resistance at 1250 °C. Results indicated that CMAS couldn't cover the whole surface of YTaO4 pellets homogeneously because of low wettability between liquid CMAS and YTaO4, in addition, there was almost no reaction layer after 4 h reaction. The XRD results showed that M-YTaO4, M′-YTaO4, Ca2Ta2O7 and Y2Si2O7 were the main four phases after reaction and there was no phase containing the elements of Mg and Al. Compared with YSZ TBCs, this new kind of potential thermal barrier ceramic material showed well resistance to CMAS corrosion.