Correlation of thermal conductivity changes with anisotropic nano-pores of EB-PVD deposited FYSZ-coatings

Electron beam physical vapour deposited (EB-PVD) FYSZ-coatings were produced in different morphologies by varying the process parameters. Anisotropic and isotropic nano-sized pores in these FYSZ-coatings were analysed by means of Small Angle Neutron Scattering (SANS). In order to differentiate closed and open pores, SANS-measurements were carried out as the coatings were immersed in matching liquid. With in-situ high-temperature SANS-measurements, the thermally activated changes of aspect ratio and surface area of the pores were observed. Thermal conductivity values of as-coated and aged coatings are measured by Laser-Flash Analysis (LFA) and have been correlated with the changes in pore shape and size. All results were compared to those previously obtained from standard EB-PVD PYSZ-coatings.