Thermal spraying techniques are used to manufacture insulating coatings especially for demanding applications like fuel cells where normal insulating materials cannot be used. In electrical insulation applications, the mostly used coating materials are aluminum oxide (Al2O3), magnesium oxide (MgO) and magnesium aluminate (MgAl2O4). Dielectric properties of thermally sprayed ceramic coatings are strongly affected by ambient conditions, and in addition to this they are not well documented in the literature. In this paper the effects of environmental conditions on certain dielectric properties of a thermally sprayed coating are studied. DC resistivity as well as permittivity and losses at different frequencies at relative humidities of 20 % and 45 % at temperature of 20 °C, 40 °C and 60 °C will be reported in the paper for Al2O3 samples sprayed using HVOF (High Velocity Oxygen Fuel) technique. DC dielectric breakdown strength is also studied for the HVOF alumina coating at temperature of 20 °C and relative humidity of 20 %. Effects of ambient conditions and coating material composition are also analyzed.
|Title of host publication||Proceedings of the 23rd Nordic Insulation Symposium|
|Subtitle of host publication||NORD-IS 2013|
|Publication status||Published - 2013|
|MoE publication type||Not Eligible|
|Event||The 23rd Nordic Insulation Symposium, NORD-IS 13 - Trondheim, Norway|
Duration: 9 Jun 2013 → 12 Jun 2013
|Conference||The 23rd Nordic Insulation Symposium, NORD-IS 13|
|Abbreviated title||NORD-IS 2013|
|Period||9/06/13 → 12/06/13|
Niittymäki, M., Rotthier, B., Suhonen, T., Metsäjoki, J., & Lahti, K. (2013). Effects of ambient conditions on the dielectric properties of thermally sprayed ceramic coating. In L. Postmyr (Ed.), Proceedings of the 23rd Nordic Insulation Symposium: NORD-IS 2013 (pp. 131-135). Akademika forlag.