Reaction products of Sm2Zr2O7 with calcium-magnesium-aluminum-silicate (CMAS) and their evolution
Yinghua Wang, Zhuang Ma, Ling Liu, Yanbo Liu
Abstract
Abstract During flight, many silicates (sand, dust, debris, fly ash, etc.) are ingested by an engine. They melt at high operating temperatures on the surface of thermal barrier coatings (TBCs) to form calcium-magnesium-aluminum-silicate (CMAS) amorphous settling. CMAS corrodes TBCs and causes many problems, such as composition segregation, degradation, cracking, and disbanding. As a new generation of TBC candidate materials, rare-earth zirconates (such as Sm 2 Zr 2 O 7 ) have good CMAS resistance properties. The reaction products of Sm 2 Zr 2 O 7 and CMAS and their subsequent changes were studied by the reaction of Sm 2 Zr 2 O 7 and excess CMAS at 1350 °C. After 1 h of reaction, Sm 2 Zr 2 O 7 powders were not completely corroded. The reaction products were Sm-apatite and c-ZrO 2 solid solution. After 4 h of reaction, all Sm 2 Zr 2 O 7 powders were completely corroded. After 24 h of reaction, Sm-apatite disappeared, and the c-ZrO 2 solid solution remained.