Abstract
A low diffusivity NiRePtAl single-phase coating was formed on a Ni3Al-based SC superalloy by electroplating and aluminizing treatments, in which the electroplating consisted of depositing Ni-Re and Pt layer. The isothermal oxidation test of the sample was evaluated at 1100 and 1200 °C; the results indicated that the low diffusivity NiRePtAl single-phase sample promoted the oxidation resistance due to a greater β-NiAl phases-enriched outer layer. The Re-base diffusion barrier could effectively refrain the outward diffusion of Mo. Low diffusivity NiRePtAl single-phase coating has a lower inter-diffusion rate to the superalloy, where the thickness of the secondary reaction zone decreased by 35%. Mechanisms responsible for improved oxidation resistance and decreased extent for the formation of secondary reaction zones are discussed in the present study.
Highlights
The single-phase NiPtAl coating, as standalone coating or bond coat of the thermal barrier coating (TBC) system, is one of the widely applied protective coatings for gas turbines in aerospace and marine due to its outstanding high-temperature oxidation and hot corrosion resistance, along with excellent thermo-fatigue properties [1,2,3,4,5]
A continuous, adherent, slow-growing protective Al2 O3 scale, which acts as a barrier against oxidation and hot corrosive attack, is usually formed at the surface of the NiPtAl coating once exposed to high temperatures
The loss of Ni from the superalloy destroys the coherent structure of the matrix and leads to the growth of the topologically close-packed (TCP) phase, which is rich in W, Mo, Re, etc
Summary
The single-phase NiPtAl coating, as standalone coating or bond coat of the thermal barrier coating (TBC) system, is one of the widely applied protective coatings for gas turbines in aerospace and marine due to its outstanding high-temperature oxidation and hot corrosion resistance, along with excellent thermo-fatigue properties [1,2,3,4,5]. A continuous, adherent, slow-growing protective Al2 O3 scale, which acts as a barrier against oxidation and hot corrosive attack, is usually formed at the surface of the NiPtAl coating once exposed to high temperatures. An interdiffusion zone (IDZ) grows in the matrix by diffusion of aluminum from the bond coating to the superalloy, which causes great consumption of Al and leads the phase transformation from β-NiAl to γ’-Ni3 Al [6,7,8].
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
