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7243 |
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Thursday, May 05, 2022, Hall -2.32/33 9:00 AM Metal Coatings I |
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Cavitation resistance of different ceramic coatings obtained by plasma and flame spraying from powder and flexicord |
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Geoffrey Darut / UTBM, France Jean-Yves Hihn / UBFC, ICB-PMDM-LERMPS, France Noura Sleiman/ UTBM, France Marie Pierre Planche*/ UTBM, France Loïc Hallez/ UBFC, UTINAM UM CNRS 6213, France Hanlin Liao/ UBFC, ICB-PMDM-LERMPS, France |
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Cavitation erosion causes damage leading to a reduced life of parts. As a result, a significant additional cost to productivity is incurred in terms of lost efficiency and increased repair costs. Therefore, protection against cavitation damages on turbine components, for example, is considered an as essential phase in the maintenance program of hydroelectric power plants. To extend their durability, components metallic surfaces are coated with a protective layer applied by welding or thermal spraying. This study investigates the impact of cavitation on several ceramics coating (Cr2O3, YSZ, Al2O3-ZrO2) in the purpose of improving their resistance properties. Different spraying processes are tested (plasma, flame) to obtain a variety of microstructures and compositions. These samples are exposed to an accelerated acoustic test using a 20 kHz vibrating device following direct (interchangeable sonotrode tip coating) or indirect (face to face) methods. The Cavitation resistance properties of these coatings were estimated and compared to each other using several methods as material weight loss, surface roughness, nature of tearing mechanisms and their impacts. Based on the analysis, several parameters are derived, notably the latency time of the phenomenon and the cumulative erosion rate. Hardness and internal stress evolution in the coatings will also be discussed. |