Correlation of Feedstock Powder Characteristics with Microstructure, Composition, and Mechanical Properties of La2Ce2O7 Coatings Produced by Plasma Spray-Physical Vapor Deposition
Abstract
:1. Introduction
2. Materials and Methods
2.1. Feedstock Fabrication
2.2. Coating Preparation
2.3. Characterization
3. Results and Discussion
3.1. Microstructure and Composition of LC Feedstocks
3.2. Microstructure of LC Coatings
3.3. Composition of LC Coatings
3.4. Nano-Indentation Tests of LC Coatings
4. Conclusions
- (1)
- Small agglomerated feedstock, weak binding strength and small primary particle sizes can enhance the feedstock evaporation rates, thus obtaining well columnar structured coatings. Nevertheless, fine particles can be co-deposition inside the columns if the powder feed rate is too high.
- (2)
- The La/Ce atomic ratios of the coatings reduced compared to those of the feedstocks, especially the coatings with better columnar structure. Thus, to achieve stoichiometric LC coatings with well columnar structure, adding reasonable excess La in the feedstock is necessary.
- (3)
- Both the hardness and Young’s modulus of each coating show negative correlations with the porosity inside the columns. To optimize the hardness and Young’s modulus simultaneously for TBCs utilization, the porosity can be modified by adjusting the powder feed rate.
Author Contributions
Funding
Acknowledgments
Conflicts of Interest
References
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Powder | Inlet Temperature (°C) | Outlet Temperature (°C) | Nozzle Rotation Speed (r/min) | Slurry Feeding Rate (L/min) |
---|---|---|---|---|
1 | 320 | 120 | 16,000 | 5 |
2 | 300 | 100 | 17,000 | 2 |
3 | 300 | 100 | 17,000 | 2 |
Plasma Gas | Ar 30 slpm 1/He 60 slpm 1 |
Power | 65 kW |
Chamber pressure | 1 mbar |
Spray time | 5 min |
Carrier gas flow | Ar 10 slpm 1 |
Spray distance | 1000 mm |
Powder | d10 (μm) | d50 (μm) | d90 (μm) |
---|---|---|---|
1 | 30 | 53 | 80 |
1 (after) | 24 | 51 | 73 |
2 | 9 | 15 | 25 |
2 (after) | 2 | 14 | 23 |
3 | 10 | 17 | 27 |
3 (after) | 1 | 8 | 23 |
No. | 1 | 2 | 3 |
---|---|---|---|
Powder | 1.24 | 1.11 | 1.48 |
Coating | 1.17 | 0.77 | 1.19 |
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Zhao, C.; He, W.; He, J.; Wei, L.; Guo, H. Correlation of Feedstock Powder Characteristics with Microstructure, Composition, and Mechanical Properties of La2Ce2O7 Coatings Produced by Plasma Spray-Physical Vapor Deposition. Coatings 2020, 10, 93. https://doi.org/10.3390/coatings10020093
Zhao C, He W, He J, Wei L, Guo H. Correlation of Feedstock Powder Characteristics with Microstructure, Composition, and Mechanical Properties of La2Ce2O7 Coatings Produced by Plasma Spray-Physical Vapor Deposition. Coatings. 2020; 10(2):93. https://doi.org/10.3390/coatings10020093
Chicago/Turabian StyleZhao, Cong, Wenting He, Jian He, Liangliang Wei, and Hongbo Guo. 2020. "Correlation of Feedstock Powder Characteristics with Microstructure, Composition, and Mechanical Properties of La2Ce2O7 Coatings Produced by Plasma Spray-Physical Vapor Deposition" Coatings 10, no. 2: 93. https://doi.org/10.3390/coatings10020093
APA StyleZhao, C., He, W., He, J., Wei, L., & Guo, H. (2020). Correlation of Feedstock Powder Characteristics with Microstructure, Composition, and Mechanical Properties of La2Ce2O7 Coatings Produced by Plasma Spray-Physical Vapor Deposition. Coatings, 10(2), 93. https://doi.org/10.3390/coatings10020093