Research on aggressiveness of CMAS+NaVO3 mixtures towards thermal barrier coatings from the perspective of physical and chemical characteristics
Huanjie Fang, Peng Zhou, Yongxin Wang, Chongqing Di, Jibin Pu
Abstract
Thermal barrier coatings (TBCs) used in marine condition recently suffer from a new degradation mainly induced by the coupling effect of calcium-magnesium-aluminum-silicate (CMAS) and molten salt . In present study, physical and chemical properties of CMAS+NaVO 3 mixture with varying CMAS/NaVO 3 ratio were examined to determine its aggressiveness towards TBCs. It was found that the crystallization behavior of CMAS was remarkably changed due to NaVO 3 addition. The experimental results also revealed a decreasing melting point and viscosity with increasing NaVO 3 content, indicating an enhanced aggressivity even at a relatively low temperature. More specifically, the Log viscosity values of the melts were found linearly dependent on NaVO 3 content. In addition, theoretical results implied that thermo-chemical damage aroused by CMAS+NaVO 3 mixtures would be potentially mitigated to a certain extent as compared with the case in CMAS corrosion.