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| Process and Properties of SrZrO3 Thermal Barrier Coating Prepared by Atmospheric Plasma Spray |
| Received:June 12, 2018 Revised:January 25, 2019 |
| View Full Text View/Add Comment Download reader |
| DOI：10.7643/ issn.1672-9242.2019.01.004 |
| KeyWord:atmospheric plasma spraying SrZrO3 thermal barrier coating phase transition |
| Author | Institution |
| MA Bo-le |
1. a. School of Materials Science and Engineering, b. School of Chemical Engineering, Inner Mongolia University of Technology, Hohhot , China |
| MA Wen |
1. a. School of Materials Science and Engineering, b. School of Chemical Engineering, Inner Mongolia University of Technology, Hohhot , China |
| HUANG Wei |
1. a. School of Materials Science and Engineering, b. School of Chemical Engineering, Inner Mongolia University of Technology, Hohhot , China |
| BAI Yu |
1. a. School of Materials Science and Engineering, b. School of Chemical Engineering, Inner Mongolia University of Technology, Hohhot , China |
| JIA Rui-ling |
1. a. School of Materials Science and Engineering, b. School of Chemical Engineering, Inner Mongolia University of Technology, Hohhot , China |
| DONG Hong-ying |
1. b. School of Chemical Engineering, Inner Mongolia University of Technology, Hohhot , China;2. Inner Mongolia Key Laboratory of Thin Film and Coatings Technology, Hohhot , China |
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| Abstract: |
| Objective To explore the optimum spray parameters of the SrZrO3 coating prepared by atmospheric plasma spray to obtain the better melted coating with higher deposition efficiency and research the thermophysical properties and thermal cycling behavior of the SrZrO3 coatings. Methods The SrZrO3 thermal barrier coatings were prepared by atmospheric plasma spray (APS). Taguchi design of experiments (DOE) was employed to investigate the effect of different spray parameters on powder melting and coating deposition efficiency; and a scanning electron microscopy (SEM) was used to analyze the melting status of the SrZrO3 coating. Thick coating was prepared with the optimized spray parameters. And the thermal expansion coefficients, sintering shrinkage kinetics and thermal diffusivities of the SrZrO3 coating were measured with high-temperature dilatometer and laser flash method, respectively. Results The highest deposition efficiency of the SrZrO3 coating was obtained at a spray distance of 90 mm, with a maximum single-pass coating thickness of 15.3 μm; while the coating melted more completely at a spray distance of 100 mm. The content of the secondary phase t-ZrO2 developed in the as-sprayed SrZrO3 decreased and disappeared gradually upon heat-treatment at 1600 ℃; while the content of m-ZrO2 gradually increased to 27 wt.% after heat-treatment at 1600 ℃ for 360 h. The thermal expansion coefficients of the SrZrO3 coating was 8-10×10?6 K?1(200 ℃- 1400 ℃), that decreased gradually upon heat-treatment. The thermal conductivity of the SrZrO3 coating increased first and then decreased with the prolonged heat-treatment time, that was 1.82 W?m?1?K?1 (1000 ℃) after heat-treatment for 360 h. The furnace cycling lifetime of the SrZrO3/YSZ double ceramic layer coating was 548 cycles with the fully spallation of the coating. Conclusion The optimum spray parameters of the SrZrO3 coating are as follows: arc current 550 A, argon flow rate 40 L/min, hydrogen flow rate 10 L/min, spray distance 100 mm, power 35.8 kW. The thermal expansion coefficient and thermal conductivity of the SrZrO3 coating decrease with an increase of the secondary phase m-ZrO2 with the prolonged heat-treatment time. The thermal cycling lifetime of the SrZrO3/YSZ double ceramic layer coating is much longer than that of the SrZrO3 single ceramic layer coating. |
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