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4681 |
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Tuesday, May 10, 2016, Auditorium 4:10 PM Young Professionals Session |
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Microstructure and thermal conductivity of Fe-based amorphous coatings prepared by HVOF thermal spraying |
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Liang Wang* / College of materials science and engineering, Beijing University of Technology, China Zheng Zhou / College of materials science and engineering,Beijing University of Technology , China Haihua Yao/ College of materials science and engineering,Beijing University of Technology , China Yiming Wang/ College of materials science and engineering,Beijing University of Technology , China Xu Wu/ College of materials science and engineering,Beijing University of Technology , China Dingyong He/ College of materials science and engineering,Beijing University of Technology , China |
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A series of Fe-based amorphous coatings (Fe59Cr12Nb5B20Si4) were designed and fabricated by High Velocity Oxygen Fuel (HVOF) spraying process on the aluminum alloy (4032) substrate with different conditions. The microstructure and the thermal conductivity of Fe-based amorphous coatings were detected by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Microhardness instruments and the Laser Flash (TC-7000H). It is founded that the coatings present a dense structure and low porosity from 1.3% to 0.7%, as the flow of oxygen and kerosene increase within the parameter rang examined. The coatings primarily consist of amorphous matrix and some precipitated nanocrystals, but the amorphous fraction of the coatings are above 75% by calculation. Depending on the structure advantage, the amorphous coatings exhibit high microhardness, and slightly going up from 1068.5 HV to 1121.2 HV with the spraying parameter increase. The thermal conductivity of the amorphous coatings were investigated. The results show that all designed coatings have a lower thermal conductivity less than 5 W/mK compared with the 304L stainless steel (15~16 W/mK). The lower thermal conductivity level may has great application potential as thermal barrier materials. Keywords: Fe-based amorphous coating, HVOF, Micro-structure, Thermal conductivity |