Internal Diameter Coating by Warm Spraying of Fine WC-12Co Powders (− 10 + 2 µm) with Very Short Spray Distances up to 10 mm
| Autor: | J. Zajaczkowski, I. Baumann, K. Schmidt, C. Schaak, Wolfgang Tillmann, G. Schmidtmann, W. Luo, Leif Hagen, G. Matthäus |
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| Rok vydání: | 2021 |
| Předmět: |
Jet (fluid)
Materials science 02 engineering and technology Plasma engineering.material 021001 nanoscience & nanotechnology Condensed Matter Physics Kinetic energy Microstructure Combustion Surfaces Coatings and Films 020303 mechanical engineering & transports 0203 mechanical engineering Coating Materials Chemistry engineering Particle Composite material 0210 nano-technology Thermal spraying |
| Zdroj: | Journal of Thermal Spray Technology. 30:1344-1364 |
| ISSN: | 1544-1016 1059-9630 |
| Popis: | The internal diameter (ID) coating by means of thermal spraying is currently experiencing growing interest in science and industry. In contrast to the well-established plasma- and arc-based spray techniques, there is a lack of knowledge concerning kinetic processes such as HVOF, HVAF and warm spray (WS). A major challenge represents the necessity of short spray distances and the compact design of novel ID spray guns with reduced combustion power. Conventional WC-Co powders (− 45 + 15 µm) are not able to achieve a sufficient heat and momentum transfer. The use of fine powders 2) “ID RED” (Thermico Engineering GmbH, Germany) was investigated. First, the flame profile as well as the in-flight behavior of the particles along the spray jet (spray distances SD = 10-80 mm) was analyzed at different nitrogen flows NF = 15-115 L/min to find suitable spray parameter intervals. Subsequently, planar steel samples were coated with SD = 10-50 mm and constant NF = 90 L/min. Analyses regarding the microstructure, the mechanical properties and the phase evolution of the coatings were performed. The aim was to study spraying with the novel ID gun and to scrutinize shortest feasible spray distances. Finally, steel tubes (internal diameter of 81.6 mm and a wall thickness of 10.0 mm) were coated with SD = 20 mm and NF = 90 L/min to investigate in how far the results can be transferred to ID parts. Correlations between the particle behavior, the microstructure and the coating properties were made. |
| Databáze: | OpenAIRE |
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