Abstract:Aluminide coating is prepared on K438 Ni-based superalloy by pack cementation. The hot corrosion test of as-received and pre-oxidation aluminide coating in Na2SO4 salt are carried out at 1050°C. The coating morphologies, phase composition, and corrosion products are characterized by XRD, SEM, EDS, and TEM. The conclusion is that the pre-oxidation aluminide coating has excellent hot corrosion properties. After hot corrosion, the oxide scale of pre-oxidation aluminide coating is the thinnest and maintains good i… Show more
“…In recent years, through studying the influence of pre-oxidation on the high-temperature oxidation and heat resistance corrosion properties of the coating, Yang [ 9 ] found that a Pt-Al-coated sample can form a continuous and dense Al 2 O 3 film after pre-oxidation treatment, which can effectively prevent molten salt from directly entering the material surface, and the pre-oxidized samples did not indicate internal oxidation or a vulcanization phenomenon. In the process of a hot corrosion experiment, the oxide film formed on the surface of the pre-oxidized Al-Si coating is thin and maintains good integrity, but the structure of the oxide film formed fluctuates greatly, indicating that the oxide film grows toward the inner layer of the coating during the process of oxidation dissolution [ 10 , 11 ]. Gao Bo et al [ 12 ] studied the influence of oxidation on the high-temperature oxidation and hot corrosion behavior of Co-Al-W-based superalloy and found that, when the alloy pre-oxidized at 950 °C under normal oxygen, partial pressure was oxidized at 1000 °C, the oxidation products fell off less, the oxidation mass gain was slowed down and the oxidation resistance of the alloy was improved.…”
Under the condition of long-time high-temperature oxidation, oxidation in Al-Si coating will lead to degradation of the coating. To solve this problem, the Al-Si coating was treated before the oxidation experiment at different pre-oxidation temperatures and times. The structure, morphology and element distribution of the oxide film were characterized by XRD, SEM and EPMA, and the oxidation kinetics curves were drawn. The results show that the oxidation resistance of the pre-oxidized samples is improved in the process of constant temperature oxidation at 1000 °C. When the pre-oxidation temperature is set at 950 °C, the mass gain of the samples is the lowest, and the accelerated decomposition of Cr2O3 caused by high pre-oxidation temperature is avoided. After oxidation for 300 h, the oxide film on the surface is still continuous and dense without peeling. The samples pre-oxidized at 950 °C for 7 h show the best oxidation resistance in a 1000 °C constant temperature oxidation process, more α-Al2O3 oxides are generated on the coating surface and the element diffusion between the matrix and the coating caused by overly long oxidation time is avoided.
“…In recent years, through studying the influence of pre-oxidation on the high-temperature oxidation and heat resistance corrosion properties of the coating, Yang [ 9 ] found that a Pt-Al-coated sample can form a continuous and dense Al 2 O 3 film after pre-oxidation treatment, which can effectively prevent molten salt from directly entering the material surface, and the pre-oxidized samples did not indicate internal oxidation or a vulcanization phenomenon. In the process of a hot corrosion experiment, the oxide film formed on the surface of the pre-oxidized Al-Si coating is thin and maintains good integrity, but the structure of the oxide film formed fluctuates greatly, indicating that the oxide film grows toward the inner layer of the coating during the process of oxidation dissolution [ 10 , 11 ]. Gao Bo et al [ 12 ] studied the influence of oxidation on the high-temperature oxidation and hot corrosion behavior of Co-Al-W-based superalloy and found that, when the alloy pre-oxidized at 950 °C under normal oxygen, partial pressure was oxidized at 1000 °C, the oxidation products fell off less, the oxidation mass gain was slowed down and the oxidation resistance of the alloy was improved.…”
Under the condition of long-time high-temperature oxidation, oxidation in Al-Si coating will lead to degradation of the coating. To solve this problem, the Al-Si coating was treated before the oxidation experiment at different pre-oxidation temperatures and times. The structure, morphology and element distribution of the oxide film were characterized by XRD, SEM and EPMA, and the oxidation kinetics curves were drawn. The results show that the oxidation resistance of the pre-oxidized samples is improved in the process of constant temperature oxidation at 1000 °C. When the pre-oxidation temperature is set at 950 °C, the mass gain of the samples is the lowest, and the accelerated decomposition of Cr2O3 caused by high pre-oxidation temperature is avoided. After oxidation for 300 h, the oxide film on the surface is still continuous and dense without peeling. The samples pre-oxidized at 950 °C for 7 h show the best oxidation resistance in a 1000 °C constant temperature oxidation process, more α-Al2O3 oxides are generated on the coating surface and the element diffusion between the matrix and the coating caused by overly long oxidation time is avoided.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.