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5187 |
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Friday, June 09, 2017, Hall 27 9:40 AM Metal Coatings |
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Characterization of vapors and droplets Al based coatings deposited by very low pressure plasma spray |
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Xiujuan Fan / University Bourgogne Franche-Comté, France Marie-Pierre Planche/ Département IMSIIRTES-LERMPSUniversité de Technologie de Belfort-Montbéliard, Belfort Geoffrey Darut*/ University Bourgogne Franche-Comté, France Nan Kang/ Département IMSIIRTES-LERMPSUniversité de Technologie de Belfort-Montbéliard, Belfort Ghislain Montavon/ Département IMSIIRTES-LERMPSUniversité de Technologie de Belfort-Montbéliard, Belfort |
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The objective of this research is primarily to investigate the microstructure and mechanical property of the coatings along the radial directions of the plasma plume during the VLPPS process. Aluminum powder was sprayed by a F100 low-power plasma gun under working pressure of 150 Pa. 10 coatings were deposited at different positions regarding the plasma plume. On the centre of the plasma plume, an inter diffusion between aluminum and some elements((such as Fe, Cr, Ni) present in the base metal takes places to form aluminum based intermetallic Al3Fe coating according to the XRD and EDS. Based on the SEM observation, the packed columnar structure mixed with nanometer particles was formed with a majority of pure vapor condensation from evaporated particles. Whereas the distance to the centre of plasma plume 15mm, 30mm, 60mm, 90mm, 120mm along the radial directions, the deposited coatings exhibite a lamellar binary structure which was formed by the mixed deposition of vapor and molten droplets. And the coatings morphologies vary from nearly dense to loose and highly porous. Finally, the hardness of typical coating hardness was investigated. The intermetallic Al3Fe coating, on the centre of the plasma plume, reached 448HV25g.f, which is much higher than the coating obtained at other position. |