Analysis of Anisotropic Void System in Electron-Beam Physical-Vapour-Deposited (EB-PVD) Thermal-Barrier Coatings

The study demonstrated processing-related morphological differences that produced three different electron-beam physical-vapor deposition (EB-PVD) partially Yttria Stabilized Zirconium (PYSZ) coatings. The thermally activated changes of the coatings were analyzed by employing a matching-mixture immersion and in situ high-temperature small-angle neutron scattering (SANS) techniques. The total surface area, pore size, pore morphology, and anisotropic changes were determined and correlated with thermally induced deviations in the thermal conductivity. EB-PVD coatings were produced by employing 'von Ardenne' pilot-plant equipment with a maximum EB power of 150 kW. Evaporation was carried out from single source that had standard chemical composition with a diameter of 62.5 mm and a length of 150 mm. The vapor phase was deposited on plane substrates under three different rotating modes by mounting the substrate in a holder with its axis perpendicular to the evaporation surface.