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

Anisotropic and nanosized pores in PYSZ-based TBCs are analysed by means of small-angle neutron scattering (SANS). Three different coating morphologies are produced by varying the process parameters. In order to differentiate between closed and open pores in 400 μm thick coatings, a contrast-matching SANS technique is employed. In situ high-temperature SANS measurements demonstrate the occurrence of thermally activated surface area and pore-surface changes. Thermally derived changes in the pore size and morphology are correlated with the thermal conductivity measured using laser-flash analysis (LFA).