| WANG Yujiang,PAN Wangshuai,WANG Xudong,YANG Kun.Effect of Aluminum-boron Nitride Powder Composite Form on Microstructure and Properties of Atmospheric Plasma-sprayed Coating[J],54(7):247-259 |
| Effect of Aluminum-boron Nitride Powder Composite Form on Microstructure and Properties of Atmospheric Plasma-sprayed Coating |
| Received:August 07, 2024 Revised:December 07, 2024 |
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| DOI：10.16490/j.cnki.issn.1001-3660.2025.07.021 |
| KeyWord:aluminum-boron nitride powder particle size composite form porosity rate hardness hBN burn-off rate abrasibility APS |
| Author | Institution |
| WANG Yujiang |
School of Mechanical and Automotive Engineering, Guangxi University of Science and Technology, Guangxi Liuzhou , China |
| PAN Wangshuai |
School of Mechanical and Automotive Engineering, Guangxi University of Science and Technology, Guangxi Liuzhou , China;a.National Engineering Laboratory of Modern Materials Surface Engineering Technology, b.Guangdong Provincial Key Laboratory of Modern Surface Engineering Technology, Institute of New Materials, Guangdong Academy of Sciences, Guangzhou , China |
| WANG Xudong |
School of Mechanical and Automotive Engineering, Guangxi University of Science and Technology, Guangxi Liuzhou , China;a.National Engineering Laboratory of Modern Materials Surface Engineering Technology, b.Guangdong Provincial Key Laboratory of Modern Surface Engineering Technology, Institute of New Materials, Guangdong Academy of Sciences, Guangzhou , China;Guangzhou GRG Metrology & Test Co., Ltd., Guangzhou , China |
| YANG Kun |
a.National Engineering Laboratory of Modern Materials Surface Engineering Technology, b.Guangdong Provincial Key Laboratory of Modern Surface Engineering Technology, Institute of New Materials, Guangdong Academy of Sciences, Guangzhou , China |
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| Abstract: |
| To investigate the melting behavior of different composite powders in flame flows and their impact on coating microstructure and performance, four types of composite powders were prepared:agglomerated type (Al-hBN), embedded type (CuAl-hBN), hBN-coated Al type (hBN/Al), and Al-coated hBN type (Al/hBN). All four powders were prepared according to the binder agglomeration process and coatings were fabricated according to the atmospheric plasma spraying technology. Subsequently, X-ray diffraction (XRD) was used for phase analyses of powders and coatings. A scanning electron microscopy (SEM) was employed for microstructural analysis of both powders and coatings. An inverted metallographic microscopy was used to characterize the coating porosity. A Rockwell hardness tester was used to measure the surface hardness of the coatings. A nitrogen-oxygen analyzer was used to assess the burn-off rate of hBN during spraying. A high-temperature friction and wear tester was used to create the test environment. An energy-dispersive spectroscopy (EDS) was used to analyze the elemental content on the worn surface of the coatings, and a three-dimensional scanner was used to scan the wear marks. The test results indicated that:Al-hBN powders had smaller particle sizes, were more prone to adhesion between particles, exhibited the poorest flowability, and the lowest feed rate; CuAl-hBN powders had relatively larger particle sizes, higher bulk density, and slightly poorer flowability; hBN/Al powders had larger and more uniform particle sizes, high sphericity, excellent flowability, and the highest feed rate; Al/hBN powders had a wide particle size distribution range, low bulk density, and poorer flowability. In terms of coating condition, Al-hBN showed good melting of the Al phase, forming a continuous layer, but the distribution of hBN was uneven, affecting the coating performance; CuAl-hBN powders dispersed Al and hBN well due to dendritic Cu, resulting in a more uniform phase distribution but also an increase in unmelted particles and large pores; In hBN/Al coatings, incomplete melting of particles and less hBN phase were observed; Al/hBN showed good melting with a clear layered structure and uniform phase distribution. The porosity, from highest to lowest, was:CuAl-hBN, hBN/Al, Al/hBN, and Al-hBN. The hardness, from highest to lowest, was:CuAl-hBN, Al-hBN, hBN/Al, and Al/hBN. Regarding hBN content, Al/hBN had larger and heavier hBN particles, which were less likely to disperse; In CuAl-hBN and hBN/Al, hBN was more prone to being crushed by large nucleating particles, leading to greater loss. In hBN/Al, hBN was more exposed to the flame flow and was more easily burnt off. While in Al/hBN, hBN was protected as a nucleating agent, resulting in the highest content. As for wear performance, the friction coefficients of the four coatings ranged from 0.6 to 1. The Al-hBN coating had the lowest friction coefficient and a smooth curve; CuAl-hBN had the highest friction coefficient with a relatively smooth curve; hBN/Al exhibited a higher friction coefficient with a serrated and fluctuating curve; Al/hBN had a curve with fluctuations during the running-in phase, but became smoother after stabilization, showing the lowest overall friction coefficient. In terms of abradable performance, the CuAl-hBN coating primarily underwent blade friction wear accompanied by adhesive wear, while the other three coatings exhibit predominantly adhesive wear when paired with TC4. All four coatings offered some level of protection to the friction pin, but the Al/hBN powder coating demonstrated the best wear performance due to the lowest adhesion and smooth wear marks during friction with TC4. |
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