Reaction products of Sm2Zr2O7 with calcium-magnesium- aluminum-silicate (CMAS) and their evolution

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 erodes TBCs and causes many problems, such as composition segregation, degradation, cracking, and disbanding. As a new generation of TBC candidate materials, rare-earth zirconates (Sm2Zr2O7) have good CMAS resistance properties. The reaction products of Sm2Zr2O7 and CMAS and their subsequent changes were studied by the reaction of Sm2Zr2O7 and excess CMAS at 1350°C. After 1 h of reaction, Sm2Zr2O7 powders were not completely eroded. The reaction products were Sm-apatite and c-ZrO2 solutions. After 4 h of reaction, all Sm2Zr2O7 powders were completely eroded. After 24 h of reaction, Sm-apatite disappeared, and the c-ZrO2 solution remained.

Effects of pellet surface roughness and pre-oxidation temperature on CMAS corrosion behavior of Ti2AlC

“…Recently, some new TBC materials, such as Sm 2 Zr 2 O 7 , LaPO 4 , and GdZr 2 O 7 , have also been developed to resist CMAS attack. These new TBC materials can react with CMAS to form a dense reaction layer, which can prevent the penetration of CMAS [15][16][17].…”

Improved wear resistance and low thermal radiative conductivity of a middle‐entropy tantalate Y0.5Gd0.5Ta0.5Nb0.5O4

“…In recent years, many promising materials have been discovered as TBCs, such as zirconates, cerates, and phosphates. [13][14][15][16] These materials show better performance than YSZ in some aspects, such as lower thermal conductivity and higher TECs, but there are disadvantages, including low fracture toughness, poor chemical compatibility with Al 2 O 3 , and high thermal radiative conductivity. Therefore, YSZ cannot be completely replaced by other materials.…”