TY - JOUR
T1 - Interaction of Gd2Si2O7 with CMAS melts for environmental barrier coatings
AU - Kim, Seung Hyeon
AU - Nagashima, Nobuo
AU - Matsushita, Yoshitaka
AU - Jang, Byung Koog
N1 - Funding Information:
This work was supported by JSPS KAKENHI Grant Number JP19K05016 , Japan.
Publisher Copyright:
© 2022 Elsevier Ltd
PY - 2023/2
Y1 - 2023/2
N2 - Environmental barrier coatings (EBCs) prevent the oxidation of ceramic matrix composites (CMC), which are used as components in gas turbines. However, EBCs deteriorate more rapidly in real environments, molten silicate deposits accelerate the deterioration of EBCs. In this study, high-temperature behavior sintered Gd2Si2O7 with calcia-magnesia-alumina-silica (CMAS) melt at 1400 °C for 0.5, 2, 12, 48, and 100 h was investigated. HT-XRD results showed that at 1300 °C, CMAS and Gd2Si2O7 chemically reacted to form Ca2Gd8(SiO4)6O2 (apatite). The reaction layer became thicker as the heat-treatment time increased, and the thickness of the reaction layer has increased following a parabolic curve. With the extension of the reaction time from 0.5 to 100 h, the thickness of the reaction layer increased from approximately 98 to 315 µm. It was confirmed that Ca2Gd8(SiO4)6O2 grew vertically on the Gd2Si2O7 surface. Vertical and horizontal cracks were found after reacting at 1400 °C for 100 h, but no interfacial delamination occurred in this study. In addition, the effects of CaO:SiO2 molar ratios, monosilicates (RE2SiO5) and disilicates (RE2Si2O7), heat-treatment time, and cation size were determined and compared with the results of previous studies (Gd2SiO5, Yb2SiO5, and Er2Si2O7).
AB - Environmental barrier coatings (EBCs) prevent the oxidation of ceramic matrix composites (CMC), which are used as components in gas turbines. However, EBCs deteriorate more rapidly in real environments, molten silicate deposits accelerate the deterioration of EBCs. In this study, high-temperature behavior sintered Gd2Si2O7 with calcia-magnesia-alumina-silica (CMAS) melt at 1400 °C for 0.5, 2, 12, 48, and 100 h was investigated. HT-XRD results showed that at 1300 °C, CMAS and Gd2Si2O7 chemically reacted to form Ca2Gd8(SiO4)6O2 (apatite). The reaction layer became thicker as the heat-treatment time increased, and the thickness of the reaction layer has increased following a parabolic curve. With the extension of the reaction time from 0.5 to 100 h, the thickness of the reaction layer increased from approximately 98 to 315 µm. It was confirmed that Ca2Gd8(SiO4)6O2 grew vertically on the Gd2Si2O7 surface. Vertical and horizontal cracks were found after reacting at 1400 °C for 100 h, but no interfacial delamination occurred in this study. In addition, the effects of CaO:SiO2 molar ratios, monosilicates (RE2SiO5) and disilicates (RE2Si2O7), heat-treatment time, and cation size were determined and compared with the results of previous studies (Gd2SiO5, Yb2SiO5, and Er2Si2O7).
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U2 - 10.1016/j.jeurceramsoc.2022.10.040
DO - 10.1016/j.jeurceramsoc.2022.10.040
M3 - Article
AN - SCOPUS:85140293990
SN - 0955-2219
VL - 43
SP - 593
EP - 599
JO - Journal of the European Ceramic Society
JF - Journal of the European Ceramic Society
IS - 2
ER -