Abstract No.:
3641

 Scheduled at:
Thursday, May 22, 2014, Hall H2 11:40 AM
Power Generation - Industrial Gas Turbines 2


 Title:
Thermal transport properties of suspension plasma sprayed yttria stabilized zirconia coatings

 Authors:
Lech Pawlowski* / University of Limoges, SPCTS UMR 6638, France
Pawel Sokolowski / SPCTS, University of Limoges, France
Stefan Kozerski/ Faculty of Mechanics, Wroclaw University of Technology, Poland
Bernard Pateyron/ SPCTS, University of Limoges, France

 Abstract:
Plasma generated by the plasma torches SG-100 and Triplex was applied to spray suspension formulated with the use of commercial fine powder ZrO2+8 wt. % Y2O3 solid phase by Tosoh. The solids have the specific surface of about 7 g/m2. The suspension was formulated with the use of solid phase, water and ethanol. The plasma spray parameters were optimized for each plasma torch separately. The operational spray parameters which were modified included: (i) electric power; (ii) working gases composition; (iii) spray distance; (iv) torch scan linear speed, and (v) substrate surface roughness. The coatings microstructure was analyzed with the use optical and scanning electron microscopy as well as X-ray diffraction. Their porosity were found with help of the image analysis of metallographically prepared cross-sections of the samples. Thermal diffusivity was measured with the use of two commercial systems, the first working at the temperatures limited to 300°C and the second one enabled to test thermal diffusivity at the temperatures up to 800°C. The measurements were made with the use of the coatings sprayed on the substrate and the 2-layers numerical model was developed to determine thermal diffusivity of the coatings. The obtained data were then associated with the measurements of coatings density and specific heat and experimentally found porosity to find thermal conductivity.

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