Calcium-Magnesium-Aluminum-Silicate (CMAS) Corrosion Resistance of Y-Yb-Gd-Stabilized Zirconia Thermal Barrier Coatings

2021 ◽  
Author(s):  
Tongxin Wang ◽  
Fang Shao ◽  
Jinxing Ni ◽  
Huayu Zhao ◽  
Yin Zhuang ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Thermal Barrier Coatings ◽  
Aluminum Silicate ◽  
Thermal Barrier ◽  
Stabilized Zirconia ◽  
Barrier Coatings ◽  
Magnesium Aluminum Silicate ◽  
Calcium Magnesium

scholarly journals Failure mechanisms of calcium magnesium aluminum silicate affected thermal barrier coatings

2017 ◽  
Vol 100 (6) ◽  
pp. 2679-2689 ◽  
Author(s):  
John Thornton ◽  
Chris Wood ◽  
Justin A. Kimpton ◽  
Mitchell Sesso ◽  
Matthew Zonneveldt ◽  
...  
Keyword(s):  
Thermal Barrier Coatings ◽  
Failure Mechanisms ◽  
Aluminum Silicate ◽  
Thermal Barrier ◽  
Barrier Coatings ◽  
Magnesium Aluminum Silicate ◽  
Calcium Magnesium

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

2021 ◽  
Author(s):  
Yinghua Wang ◽  
Zhuang Ma ◽  
Ling Liu ◽  
Yanbo Liu
Keyword(s):  
Thermal Barrier Coatings ◽  
Aluminum Silicate ◽  
Thermal Barrier ◽  
Reaction Products ◽  
Barrier Coatings ◽  
Magnesium Aluminum Silicate ◽  
Composition Segregation ◽  
Calcium Magnesium ◽  
New Generation ◽  
Sand Dust

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.

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

2021 ◽  
Author(s):  
Yinghua Wang ◽  
Zhuang Ma ◽  
Ling Liu ◽  
Yanbo Liu
Keyword(s):  
Solid Solution ◽  
Aluminum Silicate ◽  
Thermal Barrier ◽  
Reaction Products ◽  
Barrier Coatings ◽  
Magnesium Aluminum Silicate ◽  
Composition Segregation ◽  
Calcium Magnesium ◽  
New Generation ◽  
Sand Dust

AbstractDuring 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 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 corroded. The reaction products were Sm-apatite and c-ZrO2 solid solution. After 4 h of reaction, all Sm2Zr2O7 powders were completely corroded. After 24 h of reaction, Sm-apatite disappeared, and the c-ZrO2 solid solution remained.

Effect of Aluminum Phosphate Sealing Treatment on Properties of Thick Thermal Barrier Coatings

2000 ◽  
Author(s):  
S. Ahmaniemi ◽  
E. Rajamäki ◽  
P. Vuoristo ◽  
T. Mäntylä
Keyword(s):  
Corrosion Resistance ◽  
Diesel Engine ◽  
Thermal Barrier Coatings ◽  
Hot Corrosion ◽  
Aluminum Phosphate ◽  
Thermal Barrier ◽  
Stabilized Zirconia ◽  
Barrier Coatings ◽  
X Ray ◽  
Sealing Treatment

Abstract Partially stabilized zirconia (8Y2O3-ZrO2) coatings were studied as thick thermal barrier coatings (TTBCs) for diesel engine applications. To improve the hot corrosion resistance of TTBCs the 1 mm thick yttria stabilized zirconia coating was densified with aluminum phosphate based sealant. Combined with better hot corrosion resistance other benefits obtained with sealing treatment are improved adhesion as well as increased mechanical properties of the ceramic layer. Three aluminum phosphate based sealants were investigated with varying viscosity level. Different sealant viscosities were used to optimize the level of sealant penetration into the coating. Sealant penetration and the violence of the reaction were determined by XRD, SEM/EDS and optical microscopy. The hardness profile from bond coat to the surface of the top layer was determined. Coating microstructure and phase structure were characterized by optical microscopy and by X-ray diffraction. Microhardness and porosity were determined. Residual stress states were measured by X-ray based stress analyzer. Bond strength of the coatings was determined with tensile test equipment. To simulate the diesel engine combustion conditions, hot corrosion tests were performed for the sealed TTBCs. Hot corrosion resistance of the coating was tested in isothermal exposure of 60Na2SO4 - 40V2O5 melt for 48 hours at 600 °C.

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