Abstract
In general, it is accepted that thermal barrier coating (TBC) with good CMAS (CaO–MgO–Al2O3–SiO2) corrosion resistance has long lifetime. A columnar Al film was firstly deposited in this work at the top of 7wt.% yttria-stabilized zirconia (7YSZ) TBC by magnetron sputtering. Then a vacuum treatment of Al-deposited TBC was carried out at 700°C for 1h and 900°C for 5h. An α-Al2O3 layer was in situ synthesized at the top of 7YSZ TBC through the reaction of Al and ZrO2 after vacuum heat treatment. The CMAS corrosion resistance of as-sprayed TBC and treated TBC was compared after isothermal test of 1200°C for 24h. The results indicated that the Al-deposited TBC after vacuum heat treatment has better CMAS corrosion resistance than the as-sprayed TBC. Two mechanisms are considered to contribute to the protective effect of in situ synthesized α-Al2O3 layer: the first is α-Al2O3 partially filling existed open pores and cracks in the top 7YSZ coating to hinder the penetration of molten CMAS; and the second is α-Al2O3 reacted with CMAS forming CaAl2Si2O8 and MgAl2O4 that play the role in inhibiting further infiltration of CMAS.
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.
