TY - JOUR
T1 - Corrosion resistance characteristics of silicide coating on Nb–Si based alloy exposed to CMAS at high temperature
AU - Zhang, Weiping
AU - Qiao, Yanqiang
AU - Guo, Xiping
N1 - Publisher Copyright:
© 2024 Elsevier B.V.
PY - 2024/4/30
Y1 - 2024/4/30
N2 - Niobium disilicide shows good oxidation resistance in high-temperature oxidizing atmosphere and can be used as oxidation resistant coatings. However, these coatings are also required to have good environmental resistance, where corrosion by calcium‑magnesium-alumina-silicate (CMAS) represents a potential threat to the coating during the application. The aim of this work is to clarify the interaction between the Al–Y modified silicide coating on Nb–Si based alloy and the CMAS. The results indicate that the coating consists mainly of a disilicide layer and a transitional layer. The disilicide layer is mainly composed of (Nb,X)Si2 with (Zr,X′)Si2 particles dispersed in it. During the CMAS exposure, both the silicide coating and the as-formed SiO2-based composite oxide scale can be dissolved by the melted CMAS. The increase of temperature accelerates the CMAS corrosion process. The accumulation of dissolved Si at the interface between the CMAS and coating leads to the in-situ crystallization of Cristobalite-SiO2, which can arrest the melted CMAS, offering a good protection against CMAS attack. The (Nb,X)Si2 coating exhibits a two stage of CMAS corrosion process. The first one is the dissolution of the coating until SiO2 crystallization. The second one is the growth of the Cristobalite-SiO2 layer, during which the coating elements will be oxidized and can then diffuse into the melted CMAS through the Cristobalite-SiO2 layer.
AB - Niobium disilicide shows good oxidation resistance in high-temperature oxidizing atmosphere and can be used as oxidation resistant coatings. However, these coatings are also required to have good environmental resistance, where corrosion by calcium‑magnesium-alumina-silicate (CMAS) represents a potential threat to the coating during the application. The aim of this work is to clarify the interaction between the Al–Y modified silicide coating on Nb–Si based alloy and the CMAS. The results indicate that the coating consists mainly of a disilicide layer and a transitional layer. The disilicide layer is mainly composed of (Nb,X)Si2 with (Zr,X′)Si2 particles dispersed in it. During the CMAS exposure, both the silicide coating and the as-formed SiO2-based composite oxide scale can be dissolved by the melted CMAS. The increase of temperature accelerates the CMAS corrosion process. The accumulation of dissolved Si at the interface between the CMAS and coating leads to the in-situ crystallization of Cristobalite-SiO2, which can arrest the melted CMAS, offering a good protection against CMAS attack. The (Nb,X)Si2 coating exhibits a two stage of CMAS corrosion process. The first one is the dissolution of the coating until SiO2 crystallization. The second one is the growth of the Cristobalite-SiO2 layer, during which the coating elements will be oxidized and can then diffuse into the melted CMAS through the Cristobalite-SiO2 layer.
KW - Calcium‑magnesium-alumina-silicate (CMAS)
KW - Crystallization
KW - Nb–Si based alloy
KW - SiO
KW - Silicide coating
UR - http://www.scopus.com/inward/record.url?scp=85188693572&partnerID=8YFLogxK
U2 - 10.1016/j.surfcoat.2024.130699
DO - 10.1016/j.surfcoat.2024.130699
M3 - 文章
AN - SCOPUS:85188693572
SN - 0257-8972
VL - 482
JO - Surface and Coatings Technology
JF - Surface and Coatings Technology
M1 - 130699
ER -