Abstract
A novel coating system of Nb-Ni-Si intermetallic compound was designed for components serving in the aggressive environment containing molten glass. Cold spray process was employed to deposit Nb-Ni-Si coating on the nickel-based superalloy substrate (IN 718), and post-spray heat treatment was adopted to promote the formation of intermetallic compounds in the as-deposited coating. The microstructure and corrosion resistance of the coating against molten glass were investigated. Results show that the as-deposited Nb-Ni-Si coating consists of Nb, Ni and Si pure phases as that in the feedstock, which changes into NbxNiy and Nb3Ni2Si during post-treatment at 900 °C. After high-temperature oxidation test, the coating effectively suppresses the inward diffusion of oxygen under the protection of the oxidation of NiO and Nb2O5. The corrosion behavior of cold-sprayed Nb-Ni-Si coating in molten silicates 1050 °C for 50 h revealed that molten glass has penetrated the coating, but no obvious diffusion of Cr can be found at the interface between the coating and substrate. The appreciable porosity in the coating that formed during post-heat treatment accounts for the fast penetration of aggressive silicates through the coating.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: 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.