TY - JOUR
T1 - Microstructure and thermal cycling behavior of Mo(Si, Al)2 dispersed GYYSZ multilayer composite coatings on molybdenum substrate under extreme environmental conditions
AU - Sun, Zhenning
AU - Wang, Quansheng
AU - Ning, Xianjin
AU - Fan, Jiabin
AU - Li, Li
N1 - Publisher Copyright:
© 2025 Elsevier B.V.
PY - 2025/9/15
Y1 - 2025/9/15
N2 - This study presents the design of a multilayer composite coating comprising a Mo(Si, Al)2 dispersed GYYSZ composite coating, a transition coating, and a Mo(Si, Al)2 antioxidant coating. The multilayer composite coating containing 10 vol% Mo(Si, Al)2 dispersed GYYSZ is designated as “GM”. In contrast, the multilayer coating containing pure GYYSZ serves as the control group and is designated as “GZ”. The coatings were prepared on the Mo substrate by the large plasma spraying. The coatings' performance was assessed through burner rig tests under high temperatures and significant temperature gradients, with each thermal cycle lasting 25 s. The coating surface temperature reached 2700 K in the tests. The test life of the GZ coating is only 1 cycle. Due to the connection of transverse cracks and vertical cracks, the Top coat of GZ exhibits clear delamination from the Transition coat, compromising the coating's protective function. In contrast, the test life of the GM coating is >5 cycles. The GM coating after tests maintains a strong bond between the two layers, showing no significant delamination. Subsequently, a long-term test of 360 s was conducted on the GM coating. After the test, cracks appeared on the coating surface, but no delamination was observed. The Top coat of GM develops three distinct layers post-tests: a porous layer, a sintered layer, and a nonsintered layer. The porous layer results from the volatilization of gaseous products and high-temperature flame erosion. The coating of the sintered layer is densified by sintering. The formation of glassy SiO2 and Al2O3 from Mo(Si, Al)2 oxidation, along with ZrSiO4 from the reaction of SiO2 with ZrO2, effectively fills and seals the pores within the sintered layer. This enhances the coating's longevity and inhibits oxygen diffusion. The dense sintered layer, coupled with the cooling effect of high-pressure water, effectively prevents oxidation of the nonsintered layer and the underlying coating. Following the long-term test, transverse cracks developed within the sintered layer of the GM coating due to the persistent oxidation of the Mo(Si, Al)2 phase, which was detrimental to the service life of the GM coating.
AB - This study presents the design of a multilayer composite coating comprising a Mo(Si, Al)2 dispersed GYYSZ composite coating, a transition coating, and a Mo(Si, Al)2 antioxidant coating. The multilayer composite coating containing 10 vol% Mo(Si, Al)2 dispersed GYYSZ is designated as “GM”. In contrast, the multilayer coating containing pure GYYSZ serves as the control group and is designated as “GZ”. The coatings were prepared on the Mo substrate by the large plasma spraying. The coatings' performance was assessed through burner rig tests under high temperatures and significant temperature gradients, with each thermal cycle lasting 25 s. The coating surface temperature reached 2700 K in the tests. The test life of the GZ coating is only 1 cycle. Due to the connection of transverse cracks and vertical cracks, the Top coat of GZ exhibits clear delamination from the Transition coat, compromising the coating's protective function. In contrast, the test life of the GM coating is >5 cycles. The GM coating after tests maintains a strong bond between the two layers, showing no significant delamination. Subsequently, a long-term test of 360 s was conducted on the GM coating. After the test, cracks appeared on the coating surface, but no delamination was observed. The Top coat of GM develops three distinct layers post-tests: a porous layer, a sintered layer, and a nonsintered layer. The porous layer results from the volatilization of gaseous products and high-temperature flame erosion. The coating of the sintered layer is densified by sintering. The formation of glassy SiO2 and Al2O3 from Mo(Si, Al)2 oxidation, along with ZrSiO4 from the reaction of SiO2 with ZrO2, effectively fills and seals the pores within the sintered layer. This enhances the coating's longevity and inhibits oxygen diffusion. The dense sintered layer, coupled with the cooling effect of high-pressure water, effectively prevents oxidation of the nonsintered layer and the underlying coating. Following the long-term test, transverse cracks developed within the sintered layer of the GM coating due to the persistent oxidation of the Mo(Si, Al)2 phase, which was detrimental to the service life of the GM coating.
KW - Crack healing
KW - Mo(Si, Al)
KW - Multilayer composite coating
KW - Thermal cycling behavior
UR - http://www.scopus.com/pages/publications/105008175108
U2 - 10.1016/j.surfcoat.2025.132400
DO - 10.1016/j.surfcoat.2025.132400
M3 - Article
AN - SCOPUS:105008175108
SN - 0257-8972
VL - 512
JO - Surface and Coatings Technology
JF - Surface and Coatings Technology
M1 - 132400
ER -