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7436 |
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Thursday, May 05, 2022, Hall G1 5:00 PM Ceramic Coatings |
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Mechanical, electrical, tribological and corrosive properties of APS coatings from different MgO-Al2O3 feedstock powders |
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Susan Conze* / Fraunhofer IKTS, Germany Robert Vaßen / Forschungszentrum Jülich, Germany Lutz-Michael Berger/ Fraunhofer IKTS, Germany Christoph Vorkoetter/ Forschungszentrum Jülich, Germany Tobias Kalfhaus/ Forschungszentrum Jülich, Germany |
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Spinel MgAl2O4 is a known material for thermal spray coating solutions, but with a significant potential for extended use. Nine commercial and experimental MgO-Al2O3 powders with various Al2O3 contents (28 - 94 wt.%) were investigated in this study. The powders were characterized by their microstructure, particle size and phase composition depending on the powder manufacturing technology. Two experimental powder compositions (3 wt% TiO2 with 78 wt% Al2O3, 94 wt% Al2O3) were prepared based on results obtained from sintered bodies. Coatings were prepared by APS with an Ar-H2 plasma gas mixture, using a single optimized spray parameter set . The effect of different powder properties on the coating properties were studied with respect to several microstructural, mechanical, tribological, electrical and corrosive properties. The coatings were characterized for their thickness, microhardness HV0.3, and tribological (unidirectional dry sliding wear resistance), corrosion (exposure testing against H2SO4 at 80°C) and electrical (resistivity, dielectric breakdown field strength and impedance at different humidity) properties. |