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

Fingerprint

ceramic coatings
sprayed coatings
dielectric properties
coatings
microstructure
permeability
direct current
electrical resistivity
lamella
gases
humidity
voids
cracks
breakdown
ceramics
permittivity
porosity
defects
polymers

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
Niittymäki, Minna ; Rytöluoto, Ilkka ; Lahti, Kari ; Metsäjoki, Jarkko ; Suhonen, Tomi. / Role of microstructure in dielectric properties of thermally sprayed ceramic coatings. Dielectrics (ICD), 2016 IEEE International Conference on. IEEE Institute of Electrical and Electronic Engineers , 2016. pp. 1102-1105
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title = "Role of microstructure in dielectric properties of thermally sprayed ceramic coatings",
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.",
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author = "Minna Niittym{\"a}ki and Ilkka Ryt{\"o}luoto and Kari Lahti and Jarkko Mets{\"a}joki and Tomi Suhonen",
year = "2016",
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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. IEEE Institute of Electrical and Electronic Engineers , pp. 1102-1105, 1st International Conference on Dielectrics, ICD 2016, Montpellier, France, 3/07/16. https://doi.org/10.1109/ICD.2016.7547811

Role of microstructure in dielectric properties of thermally sprayed ceramic coatings. / Niittymäki, Minna; Rytöluoto, Ilkka; Lahti, Kari; Metsäjoki, Jarkko; Suhonen, Tomi.

Dielectrics (ICD), 2016 IEEE International Conference on. IEEE Institute of Electrical and Electronic Engineers , 2016. p. 1102-1105.

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

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T1 - Role of microstructure in dielectric properties of thermally sprayed ceramic coatings

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AU - Suhonen, Tomi

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N2 - 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.

AB - 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.

KW - alumina

KW - breakdown

KW - ceramic

KW - coating

KW - microstructure

KW - permittivity

KW - Porosity

KW - resistivity

KW - spinel

KW - spray

KW - thermal

KW - ProperTune

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