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Y2O3 stabilized ZrO2 (YSZ) thermal barrier coatings (TBCs) are prone to hot corrosion by molten salts. In this study, the microstructure of atmospheric plasma spraying YSZ TBCs is modified by laser glazing in order to improve the corrosion resistance. By optimizing the laser parameters, a ~18 μm smooth glazed layer with some vertical cracks was produced on the coating surfaces. The as-sprayed and modified coatings were both exposed to hot corrosion tests at 700 and 1000 ℃ for 4 h in V2O5 molten salt, and the results revealed that the modified one had improved corrosion resistance. After hot corrosion, the glazed layer kept structural integrity, with little evidence of dissolution. However, the vertical cracks in the glazed layer acted as the paths for molten salt penetration, accelerating the corrosion of the non-modified coating. Further optimization of the glazed layer is needed in the future work.


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Microstructure modification of Y2O3 stabilized ZrO2 thermal barrier coatings by laser glazing and the effects on the hot corrosion resistance

Show Author's information Lei GUOa,b( )Hui XINaZhao ZHANGcXinmu ZHANGaFuxing YEa,b
School of Materials Science and Engineering, Tianjin University, Tianjin 300072, China
Tianjin Key Laboratory of Advanced Joining Technology, Key Lab of Advanced Ceramics and Machining Technology of Ministry of Education, Tianjin 300072, China
School of Materials Science and Engineering, Liaocheng University, Liaocheng 252059, China

Abstract

Y2O3 stabilized ZrO2 (YSZ) thermal barrier coatings (TBCs) are prone to hot corrosion by molten salts. In this study, the microstructure of atmospheric plasma spraying YSZ TBCs is modified by laser glazing in order to improve the corrosion resistance. By optimizing the laser parameters, a ~18 μm smooth glazed layer with some vertical cracks was produced on the coating surfaces. The as-sprayed and modified coatings were both exposed to hot corrosion tests at 700 and 1000 ℃ for 4 h in V2O5 molten salt, and the results revealed that the modified one had improved corrosion resistance. After hot corrosion, the glazed layer kept structural integrity, with little evidence of dissolution. However, the vertical cracks in the glazed layer acted as the paths for molten salt penetration, accelerating the corrosion of the non-modified coating. Further optimization of the glazed layer is needed in the future work.

Keywords: thermal barrier coatings (TBCs), air plasma spraying (APS), Y2O3 stabilized ZrO2, microstructure modification, laser glazing, V2O5 corrosion

References(39)

[1]
R Vaßen, MO Jarligo, T Steinke, et al. Overview on advanced thermal barrier coatings. Surf Coat Technol 2010, 205: 938-942.
[2]
PP Liang, SJ Dong, JY Zeng, et al. La2Hf2O7 ceramics as potential top-coat materials for thermal/environmental barrier coatings. Ceram Int 2019, 45: 22432-22436.
[3]
B Cheng, GJ Yang, Q Zhang, et al. Gradient thermal cyclic behaviour of La2Zr2O7/YSZ DCL-TBCs with equivalent thermal insulation performance. J Eur Ceram Soc 2018, 38: 1888-1896.
[4]
DR Clarke, M Oechsner, NP Padture. Thermal-barrier coatings for more efficient gas-turbine engines. MRS Bull 2012, 37: 891-898.
[5]
DR Clarke, SR Phillpot. Thermal barrier coating materials. Mater Today 2005, 8: 22-29.
[6]
WG Mao, YJ Wang, J Shi, et al. Bending fracture behavior of freestanding (Gd0.9Yb0.1)2Zr2O7 coatings by using digital image correlation and FEM simulation with 3D geometrical reconstruction. J Adv Ceram 2019, 8: 564-575.
[7]
GR Li, GJ Yang. Understanding of degradation-resistant behavior of nanostructured thermal barrier coatings with bimodal structure. J Mater Sci Technol 2019, 35: 231-238.
[8]
HJ Rätzer-Scheibe, U Schulz. The effects of heat treatment and gas atmosphere on the thermal conductivity of APS and EB-PVD PYSZ thermal barrier coatings. Surf Coat Technol 2007, 201: 7880-7888.
[9]
S Sampath, U Schulz, MO Jarligo, et al. Processing science of advanced thermal-barrier systems. MRS Bull 2012, 37: 903-910.
[10]
HB Guo, SK Gong, CG Zhou, et al. Investigation on hot-fatigue behaviors of gradient thermal barrier coatings by EB-PVD. Surf Coat Technol 2001, 148: 110-116.
[11]
XL Chen, Y Zhao, LJ Gu, et al. Hot corrosion behaviour of plasma sprayed YSZ/LaMgAl11O19 composite coatings in molten sulfate–vanadate salt. Corros Sci 2011, 53: 2335-2343.
[12]
HF Liu, X Xiong, XB Li, et al. Hot corrosion behavior of Sc2O3–Y2O3–ZrO2 thermal barrier coatings in presence of Na2SO4+V2O5 molten salt. Corros Sci 2014, 85: 87-93.
[13]
L Guo, Z Yan, JX Yu, et al. Hot corrosion behavior of TiO2 doped, Yb2O3 stabilized zirconia exposed to V2O5 + Na2SO4 molten salt at 700–1000 ℃. Ceram Int 2018, 44: 261-268.
[14]
A Afrasiabi, M Saremi, A Kobayashi. A comparative study on hot corrosion resistance of three types of thermal barrier coatings: YSZ, YSZ+Al2O3 and YSZ/Al2O3. Mat Sci Eng A 2008, 478: 264-269.
[15]
H Jamali, R Mozafarinia, R Shoja-Razavi, et al. Comparison of hot corrosion behaviors of plasma-sprayed nanostructured and conventional YSZ thermal barrier coatings exposure to molten vanadium pentoxide and sodium sulfate. J Eur Ceram Soc 2014, 34: 485-492.
[16]
G Sivakumar, S Banerjee, VS Raja, et al. Hot corrosion behavior of plasma sprayed powder-solution precursor hybrid thermal barrier coatings. Surf Coat Technol 2018, 349: 452-461.
[17]
MH Habibi, SM Guo. The hot corrosion behavior of plasma sprayed zirconia coatings stabilized with yttria, ceria, and titania in sodium sulfate and vanadium oxide. Mater Corros 2015, 66: 270-277.
[18]
MR Loghman-Estarki, R Shoja Razavi, H Edris, et al. Comparison of hot corrosion behavior of nanostructured ScYSZ and YSZ thermal barrier coatings. Ceram Int 2016, 42: 7432-7439.
[19]
F Li, L Zhou, JX Liu, et al. High-entropy pyrochlores with low thermal conductivity for thermal barrier coating materials. J Adv Ceram 2019, 8: 576-582.
[20]
RB Zhu, JP Zou, J Mao, et al. Fabrication and growing kinetics of highly dispersed gadolinium zirconate nanoparticles. Research and Application of Materials Science 2019, 1: 28-34.
[21]
PC Tsai, JH Lee, CS Hsu. Hot corrosion behavior of laser-glazed plasma-sprayed yttria-stabilized zirconia thermal barrier coatings in the presence of V2O5. Surf Coat Technol 2007, 201: 5143-5147.
[22]
R Ghasemi, R Shoja-Razavi, R Mozafarinia, et al. The influence of laser treatment on hot corrosion behavior of plasma-sprayed nanostructured yttria stabilized zirconia thermal barrier coatings. J Eur Ceram Soc 2014, 34: 2013-2021.
[23]
P Yi, J Mostaghimi, L Pershin, et al. Effects of laser surface remelting on the molten salt corrosion resistance of yttria-stabilized zirconia coatings. Ceram Int 2018, 44: 22645-22655.
[24]
Z Soleimanipour, S Baghshahi, R Shoja-Razavi, et al. Hot corrosion behavior of Al2O3 laser clad plasma sprayed YSZ thermal barrier coatings. Ceram Int 2016, 42: 17698-17705.
[25]
Y Wang, G Darut, XT Luo, et al. Influence of preheating processes on the microstructure of laser glazed YSZ coatings. Ceram Int 2017, 43: 4606-4611.
[26]
ZJ Fan, KD Wang, X Dong, et al. The role of the surface morphology and segmented cracks on the damage forms of laser re-melted thermal barrier coatings in presence of a molten salt (Na2SO4+V2O5). Corros Sci 2017, 115: 56-67.
[27]
Z Yan, L Guo, ZH Li, et al. Effects of laser glazing on CMAS corrosion behavior of Y2O3 stabilized ZrO2 thermal barrier coatings. Corros Sci 2019, 157: 450-461.
[28]
L Guo, MZ Li, FX Ye. Phase stability and thermal conductivity of RE2O3 (RE=La, Nd, Gd, Yb) and Yb2O3 co-doped Y2O3 stabilized ZrO2 ceramics. Ceram Int 2016, 42: 7360-7365.
[29]
CL Zhang, MZ Li, YC Zhang, et al. Hot corrosion behavior of (Gd0.9Sc0.1)2Zr2O7 in V2O5 molten salt at 700–1000 °C. Ceram Int 2017, 43: 9041-9046.
[30]
MZ Li, YX Cheng, L Guo, et al. Preparation of nanostructured Gd2Zr2O7–LaPO4 thermal barrier coatings and their calcium-magnesium-alumina-silicate (CMAS) resistance. J Eur Ceram Soc 2017, 37: 3425-3434.
[31]
JS Wang, JB Sun, BL Zou, et al. Hot corrosion behaviour of nanostructured zirconia in molten NaVO3 salt. Ceram Int 2017, 43: 10415-10427.
[32]
MR Loghman-Estarki, M Nejati, H Edris, et al. Evaluation of hot corrosion behavior of plasma sprayed scandia and yttria co-stabilized nanostructured thermal barrier coatings in the presence of molten sulfate and vanadate salt. J Eur Ceram Soc 2015, 35: 693-702.
[33]
MG Gok, G Goller. Microstructural evaluation of laser remelted gadolinium zirconate thermal barrier coatings. Surf Coat Technol 2015, 276: 202-209.
[34]
R Ahmadi-Pidani, R Shoja-Razavi, R Mozafarinia, et al. Laser surface modification of plasma sprayed CYSZ thermal barrier coatings. Ceram Int 2013, 39: 2473-2480.
[35]
R Ahmadi-Pidani, R Shoja-Razavi, R Mozafarinia, et al. Improving the hot corrosion resistance of plasma sprayed ceria–yttria stabilized zirconia thermal barrier coatings by laser surface treatment. Mater Des 2014, 57: 336-341.
[36]
R Lima, A Kucuk, C Berndt. Integrity of nanostructured partially stabilized zirconia after plasma spray processing. Mat Sci Eng A 2001, 313: 75-82.
[37]
M Rahaman, J Gross, R Dutton, et al. Phase stability, sintering, and thermal conductivity of plasma-sprayed ZrO2–Gd2O3 compositions for potential thermal barrier coating applications. Acta Mater 2006, 54: 1615-1621.
[38]
XH Zhong, YM Wang, ZH Xu, et al. Hot-corrosion behaviors of overlay-clad yttria-stabilized zirconia coatings in contact with vanadate–sulfate salts. J Eur Ceram Soc 2010, 30: 1401-1408.
[39]
L Guo, CL Zhang, MZ Li, et al. Hot corrosion evaluation of Gd2O3–Yb2O3 co-doped Y2O3 stabilized ZrO2 thermal barrier oxides exposed to Na2SO4+V2O5 molten salt. Ceram Int 2017, 43: 2780-2785.
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Publication history

Received: 13 August 2019
Revised: 03 January 2020
Accepted: 14 January 2020
Published: 11 March 2020
Issue date: April 2020

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© The author(s) 2020

Acknowledgements

This research is sponsored by the National Natural Science Foundation of China (Grant No. 51971156).

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