TY - JOUR
T1 - Thermal durability of ytterbium silicate environmental barrier coating prepared by suspension plasma spray
AU - Park, Soo Min
AU - Nahm, Sahn
AU - Oh, Yoon Suk
N1 - Funding Information:
This work was supported by the research fund of the Strategic Core Material Technology Development Project (# 10065691) of the Ministry of Trade, Industry and Energy, Rep. of Korea.
Publisher Copyright:
© 2020, The Korean Ceramic Society.
PY - 2021/3
Y1 - 2021/3
N2 - Owing to their superior high-temperature stability, SiC-based ceramic matrix composites are widely used in turbine engine components for launch vehicles and other applications in the aerospace industry. However, because of the deterioration that occurs in these materials in high-temperature wet operating environments, researchers have developed environmental barrier coating technologies to protect the substrate. In this study, a top coat was prepared using Yb2SiO5 and Yb2Si2O7 as the third-generation coating of a rare-earth silicate with high thermal, chemical, and mechanical stability in high-temperature environments above 1400 °C. A new bond coat was prepared, incorporating Si, whose thermal expansion coefficient is similar to that of the SiC substrate, and Hf, which is expected to significantly contribute to high-temperature stability. The coating was prepared by suspension plasma spraying rather than atmospheric plasma spraying to realize a fine coating particle structure; to densify the coating layers, secondary densification coatings were created using ytterbium (III) nitrate pentahydrate (Yb(NO3)3∙5H2O) and tetraethyl orthosilicate (C8H20O4Si). The prepared specimens were measured in terms of weight change and weight change ratio with respect to temperature under high-temperature flames (1400 ℃ and 1700 ℃). After the secondary densification coating, the microstructure of the specimen was observed to be denser and the surface layer of the coating exhibited crystallinity. For the tested samples, a decrease in weight was observed. The largest weight loss was observed under the 1700 ℃ flame.
AB - Owing to their superior high-temperature stability, SiC-based ceramic matrix composites are widely used in turbine engine components for launch vehicles and other applications in the aerospace industry. However, because of the deterioration that occurs in these materials in high-temperature wet operating environments, researchers have developed environmental barrier coating technologies to protect the substrate. In this study, a top coat was prepared using Yb2SiO5 and Yb2Si2O7 as the third-generation coating of a rare-earth silicate with high thermal, chemical, and mechanical stability in high-temperature environments above 1400 °C. A new bond coat was prepared, incorporating Si, whose thermal expansion coefficient is similar to that of the SiC substrate, and Hf, which is expected to significantly contribute to high-temperature stability. The coating was prepared by suspension plasma spraying rather than atmospheric plasma spraying to realize a fine coating particle structure; to densify the coating layers, secondary densification coatings were created using ytterbium (III) nitrate pentahydrate (Yb(NO3)3∙5H2O) and tetraethyl orthosilicate (C8H20O4Si). The prepared specimens were measured in terms of weight change and weight change ratio with respect to temperature under high-temperature flames (1400 ℃ and 1700 ℃). After the secondary densification coating, the microstructure of the specimen was observed to be denser and the surface layer of the coating exhibited crystallinity. For the tested samples, a decrease in weight was observed. The largest weight loss was observed under the 1700 ℃ flame.
KW - Environmental barrier coatings
KW - Secondary densification coatings
KW - Si–Hf bond coat
KW - Suspension plasma spray
KW - Ytterbium silicate
UR - http://www.scopus.com/inward/record.url?scp=85092580459&partnerID=8YFLogxK
U2 - 10.1007/s43207-020-00086-1
DO - 10.1007/s43207-020-00086-1
M3 - Article
AN - SCOPUS:85092580459
SN - 1229-7801
VL - 58
SP - 192
EP - 200
JO - Journal of the Korean Ceramic Society
JF - Journal of the Korean Ceramic Society
IS - 2
ER -