An improvement in the corrosion resistance of alloys at elevated temperature is a factor for their potential use in gas turbines. In this study, Co Ni Cr Al Y has been coated on the L605 alloy using air plasma spray(A...An improvement in the corrosion resistance of alloys at elevated temperature is a factor for their potential use in gas turbines. In this study, Co Ni Cr Al Y has been coated on the L605 alloy using air plasma spray(APS) and high-velocity oxygen fuel(HVOF) coating techniques to enhance its corrosion resistance. Hot corrosion studies were conducted on uncoated and coated samples in a molten salt environment at 850°C under cyclic conditions. Thermogravimetric analysis was used to determine the corrosion kinetics. The samples were subjected to scanning electron microscopy, energy-dispersive spectroscopy, and X-ray diffraction for further investigation. In coated samples, the formation of Al2O3 and Cr2O3 in the coating acts as a diffusion barrier that could resists the inward movement of the corrosive species present in the molten salt. Coated samples showed very less spallation, lower weight gain, less porosity, and internal oxidation as compared to uncoated sample.HVOF-coated sample showed greater corrosion resistance and inferred that this is the best technique under these conditions.展开更多
In this work,the stability of passive film for long-time immersed Cu-bearing L605(L605-Cu) alloy in the phosphate buffer solution(PBS) was studied by potentiodynamic polarization and electrochemical impedance spectros...In this work,the stability of passive film for long-time immersed Cu-bearing L605(L605-Cu) alloy in the phosphate buffer solution(PBS) was studied by potentiodynamic polarization and electrochemical impedance spectroscopy.The results showed that the impedance of passive film for L605-Cu alloy experienced an initial increase and subsequent stabilization with the increase in the immersion time.In addition,the plate count method was employed to assess the antibacterial durability of L605-Cu alloy against Escherichia coli after long-time immersion.The results indicated that the antibacterial rate of L605-Cu alloy presented a declining tendency with the immersion time prolonging.X-ray photoelectron spectroscopy(XPS) was used to analyze the change of the chemical composition in the passive film on L605-Cu alloy immersed in the PBS for different time.The results showed that Cu content and its compounds in the passive film gradually increased with the immersion time prolonging,hinting declined activity of Cu ions penetrating into the passive film,which resulted in a decrease in the antibacterial performance.展开更多
文摘An improvement in the corrosion resistance of alloys at elevated temperature is a factor for their potential use in gas turbines. In this study, Co Ni Cr Al Y has been coated on the L605 alloy using air plasma spray(APS) and high-velocity oxygen fuel(HVOF) coating techniques to enhance its corrosion resistance. Hot corrosion studies were conducted on uncoated and coated samples in a molten salt environment at 850°C under cyclic conditions. Thermogravimetric analysis was used to determine the corrosion kinetics. The samples were subjected to scanning electron microscopy, energy-dispersive spectroscopy, and X-ray diffraction for further investigation. In coated samples, the formation of Al2O3 and Cr2O3 in the coating acts as a diffusion barrier that could resists the inward movement of the corrosive species present in the molten salt. Coated samples showed very less spallation, lower weight gain, less porosity, and internal oxidation as compared to uncoated sample.HVOF-coated sample showed greater corrosion resistance and inferred that this is the best technique under these conditions.
基金financially supported by the National Natural Science Foundation of China (Nos.51771199, 51631009 and 51501188)the National Key Research and Development Program (No.2016YFB0300205)。
文摘In this work,the stability of passive film for long-time immersed Cu-bearing L605(L605-Cu) alloy in the phosphate buffer solution(PBS) was studied by potentiodynamic polarization and electrochemical impedance spectroscopy.The results showed that the impedance of passive film for L605-Cu alloy experienced an initial increase and subsequent stabilization with the increase in the immersion time.In addition,the plate count method was employed to assess the antibacterial durability of L605-Cu alloy against Escherichia coli after long-time immersion.The results indicated that the antibacterial rate of L605-Cu alloy presented a declining tendency with the immersion time prolonging.X-ray photoelectron spectroscopy(XPS) was used to analyze the change of the chemical composition in the passive film on L605-Cu alloy immersed in the PBS for different time.The results showed that Cu content and its compounds in the passive film gradually increased with the immersion time prolonging,hinting declined activity of Cu ions penetrating into the passive film,which resulted in a decrease in the antibacterial performance.
