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Gadolinium zirconate (GZ) is a promising candidate for next-generation thermal barrier coating (TBC) materials. Its corrosion resistance against calcium–magnesium–alumino–silicate (CMAS) needs to be further increased for enhancing its in-service life. As the Gd element plays an important role in the CMAS resistance, three GZ coatings (GZ-0.75, GZ-1.0, and GZ-1.2) with different Gd/Zr atomic ratios are designed and deposited by laser enhanced chemical vapor deposition (LCVD) in this work. It is found that the generated Gd-apatite in GZ-1.2 would block micro-cracks inside the column structure and the inter-columnar gap more efficiently. Thus, the CMAS penetration rate (5.2 μm/h) of GZ-1.2 decreases over 27% comparing with GZ-1.0 and GZ-0.75, which is even lower than the Gd2Zr2O7 coatings fabricated by electron-beam physical vapor depositions (EB-PVDs). This work provides a feasible way to adjust the coating’s corrosion resistance and may guide the development of future coating for long in-service life.


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Corrosion resistance of non-stoichiometric gadolinium zirconate fabricated by laser-enhanced chemical vapor deposition

Show Author's information Chengguan ZHANGYun FANJuanli ZHAOGuang YANGHongfei CHENLiangmiao ZHANGYanfeng GAOBin LIU( )
School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China

Abstract

Gadolinium zirconate (GZ) is a promising candidate for next-generation thermal barrier coating (TBC) materials. Its corrosion resistance against calcium–magnesium–alumino–silicate (CMAS) needs to be further increased for enhancing its in-service life. As the Gd element plays an important role in the CMAS resistance, three GZ coatings (GZ-0.75, GZ-1.0, and GZ-1.2) with different Gd/Zr atomic ratios are designed and deposited by laser enhanced chemical vapor deposition (LCVD) in this work. It is found that the generated Gd-apatite in GZ-1.2 would block micro-cracks inside the column structure and the inter-columnar gap more efficiently. Thus, the CMAS penetration rate (5.2 μm/h) of GZ-1.2 decreases over 27% comparing with GZ-1.0 and GZ-0.75, which is even lower than the Gd2Zr2O7 coatings fabricated by electron-beam physical vapor depositions (EB-PVDs). This work provides a feasible way to adjust the coating’s corrosion resistance and may guide the development of future coating for long in-service life.

Keywords: thermal barrier coating (TBC), corrosion resistance, gadolinium zirconate (GZ), nonstoichiometry

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Publication history
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Publication history

Received: 11 September 2020
Revised: 24 December 2020
Accepted: 24 December 2020
Published: 26 April 2021
Issue date: June 2021

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© The Author(s) 2020

Acknowledgements

This work was supported by the Natural Science Foundation of Shanghai (No. 20ZR1419200), National Natural Science Foundation of China (Nos. 52072232 and 52072231), and the Program for Professor of Special Appointment (Eastern Scholar) by Shanghai Municipal Education Commission (No. TP2015040).

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