Role of microstructure in dielectric properties of thermally sprayed ceramic coatings

Minna Niittymäki, Ilkka Rytöluoto, Kari Lahti, Jarkko Metsäjoki, Tomi Suhonen

    Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientificpeer-review

    3 Citations (Scopus)

    Abstract

    Thermally sprayed insulating ceramic coatings can be utilized in conditions where polymers are inapplicable. The coatings exhibit a special lamellar microstructure with interfaces and some defects (e.g. voids, cracks) in between. The aim of this study was to analyze the relationship between the microstructural features and the dielectric properties of various thermally sprayed ceramics. The structural characterization of the ceramic coatings was made based on following properties: porosity, volumetric gas permeability and the characteristic size of crystalline lamella. High gas permeability of the coatings decreased the breakdown strength but similar effect cannot be seen in the DC resistivity and the permittivity results. Decrease of DC resistivity at high humidity did not correlate to microstructural properties; rather it is speculated to indicate the hydrophilic nature of the coatings. The characteristic crystalline domain sizes showed no clear correlation with the dielectric properties.
    Original languageEnglish
    Title of host publicationDielectrics (ICD), 2016 IEEE International Conference on
    PublisherIEEE Institute of Electrical and Electronic Engineers
    Pages1102-1105
    ISBN (Electronic)978-1-5090-2804-7, 978-1-5090-2805-4
    DOIs
    Publication statusPublished - 23 Aug 2016
    MoE publication typeA4 Article in a conference publication
    Event1st International Conference on Dielectrics, ICD 2016 - Montpellier, France
    Duration: 3 Jul 20167 Jul 2016
    Conference number: 1

    Conference

    Conference1st International Conference on Dielectrics, ICD 2016
    Abbreviated titleICD 2016
    CountryFrance
    CityMontpellier
    Period3/07/167/07/16

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    Keywords

    • alumina
    • breakdown
    • ceramic
    • coating
    • microstructure
    • permittivity
    • Porosity
    • resistivity
    • spinel
    • spray
    • thermal
    • ProperTune

    Cite this

    Niittymäki, M., Rytöluoto, I., Lahti, K., Metsäjoki, J., & Suhonen, T. (2016). Role of microstructure in dielectric properties of thermally sprayed ceramic coatings. In Dielectrics (ICD), 2016 IEEE International Conference on (pp. 1102-1105). IEEE Institute of Electrical and Electronic Engineers . https://doi.org/10.1109/ICD.2016.7547811