Corrosion behavior of CMAS-infiltrated Ba(Mg_1/3Ta_2/3)O₃ ceramic based on material characteristics

Calcium–magnesium–alumina–silicate (CMAS) corrosion is inevitable in thermal barrier coating applications. Herein, Ba(Mg_1/3Ta_2/3)O₃ (BMT) ceramic, which is a promising thermal barrier coating material, was prepared using a solid-state reaction sintering method. The effects of the surface roughness and bulk density on the CMAS corrosion behavior of BMT ceramic were analyzed by investigating the surface morphology, cross-sectional microstructure, compositional evolution, and CMAS wetting behavior before and after CMAS corrosion. The results indicate that the wettability of CMAS on the BMT bulk material with a low surface roughness was lower than that of the material with a high surface roughness owing to the smaller driving capillary force, actual contact area between CMAS and the surface, and CMAS infiltration direction in BMT with a low surface roughness. This effectively inhibited the infiltration of CMAS and reduced its corrosion effect on BMT ceramic. The infiltration of CMAS into the BMT bulk materials with a high density was weaker because there were few channels, such as pores and microcracks, for infiltration. Therefore, reducing the surface roughness and increasing the density of BMT ceramic can be considered an effective method for improving its CMAS corrosion resistance.