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5367 |
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Thursday, June 08, 2017, Hall 28 10:20 AM Modeling & Simulation I |
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Numerical investigation of the melting degree of ceramic powder particles during air plasma spraying |
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Ilkin Alkhasli* / RWTH Aachen University, Germany Kirsten Bobzin / RWTH Aachen University, IOT - Surface Engineering Institute, Germany Mehmet Öte/ RWTH Aachen University, IOT - Surface Engineering Institute, Germany Martin Knoch/ RWTH Aachen University, IOT - Surface Engineering Institute, Germany Uwe Reisgen/ RWTH Aachen University, ISF Welding and Joining Institute, Germany Oleg Mokrov/ RWTH Aachen University, ISF Welding and Joining Institute, Germany Oleksii Lisnyi/ RWTH Aachen University, ISF Welding and Joining Institute, Germany |
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Air plasma spraying is a variation of thermal spraying that is used for the production of thermal barrier and wear resistant coatings. High plasma temperatures enable the processing of the ceramic powder particles which have a high melting point and cannot be processed otherwise. Due to their low heat conductance, the ceramic particles are not necessarily fully melted during their flight in the free jet and prior to the impact on the substrate surface. Experimental particle temperature measurements by means of particle diagnostics systems deliver merely the surface temperature of the particles while the melting degree of the ceramic particles remains unknown. Therefore, the temperature field within spherical Al2O3 particles is numerically investigated for commonly used particle size distribution by considering ten size fractions between 10 and 100 µm. The model includes a two-way coupled particle-laden free jet model and takes melting heat as well as the heat of evaporation and mass loss due to evaporation into account. The effect of the spraying parameters as well as the particle injection rate on the amount of the molten particles in the given powder size distribution is determined. |