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2155 |
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Tuesday, May 04, 2010, Sophia Room 12:20 PM Properties 1 |
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Comparative study of the electrical properties and microstructures of the spinel and alumina coatings |
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Filofteia-Laura Toma* / Fraunhofer IWS, Germany Lutz-Michael Berger/ Fraunhofer Institute Material and Beam Technology (IWS), Germany Stefan Scheitz/ Fraunhofer Institute Material and Beam Technology (IWS), Germany Viktar Sauchuk/ Fraunhofer Institute for Ceramic Technologies and Systems (IKTS), Germany Mihails Kusnezoff/ Fraunhofer Institute for Ceramic Technologies and Systems (IKTS) , Germany |
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In the present work, APS and HVOF processes have been used to prepare magnesium aluminate spinel (MgAl2O4) and alumina (Al2O3) coatings for insulating applications. The microstructure and the phase composition of the coatings were evaluated by SEM and XRD analysis. Different methods have been used to investigate the electrical properties of the coatings: direct current method, electrical impedance spectroscopy and dielectric breakdown test. The isolation resistance was measured at room temperature at different humidity levels. Differences in the insulating properties due to the nature of the coating, the obtained microstructure and the measurement method used for electrical characterization are discussed. |