Journal
SURFACE & COATINGS TECHNOLOGY
Volume 446, Issue -, Pages -Publisher
ELSEVIER SCIENCE SA
DOI: 10.1016/j.surfcoat.2022.128799
Keywords
Thermal barrier coatings; Atmospheric plasma spraying; Al2O3/YSZ composite coating; CMAS corrosion
Funding
- National Natural Science Foundation of China [52105375]
- Shandong Provincial Natural Science Foundation [ZR2020QE023]
- Guangdong Basic and Applied Basic Research Foundation [2020A1515110849]
Ask authors/readers for more resources
In this study, the resistance to CMAS corrosion of Al2O3/YSZ TBCs with different Al2O3 additions was compared to 7YSZ TBCs. It was found that increasing the Al2O3 addition restricted the depth of the thermo-chemical reaction zone and promoted anorthite crystallization, improving the CMAS corrosion resistance.
Thermal barrier coatings (TBCs), exposed to the molten calcium-magnesium-aluminum-silicate (CMAS) deposits, could become degraded more readily during service. In this paper, the composite Al2O3/YSZ TBCs with different Al2O3 additions were prepared through the atmospheric plasma spraying technique and their resistance to CMAS corrosion at 1250 degrees C was carefully compared to the 7YSZ (7 wt.% Y2O3 stabilized ZrO2) TBCs. It was found that two distinct microstructural characteristics, i.e. thermo-chemical reaction zone and CMAS physical-infiltration zone, were identified for both the 7YSZ coating and the 10 wt.%Al2O3-7YSZ coating. The thermo-chemical reaction zone was severely corroded by molten CMAS, inducing the dissolution and re-precipitation of YSZ material and generating small globular m-ZrO2 particles. Furthermore, these two coatings were completely infiltrated (approximately 300 mu m) and developed significant macroscopic bending. With the Al2O3 addition increasing above 20 wt.%, the depth of the thermo-chemical reaction zone was restricted to 35 mu m without obvious CMAS physical-infiltration. During CMAS attacking the Al2O3/YSZ coating, continuous dissolution of Al2O3 into CMAS melt could promote anrthite crystallization along the CMAS-coating interface, which effectively restrained CMAS penetration and improved CMAS corrosion resistance.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available