Abstract
The aim of this work is to fabricate nanostructured ceramic coatings using unsintered agglomerated powder and to characterize differences in microstructure, especially those at the nanoscale, due to spraying conditions. Feedstock powders were prepared from commercial YSZ nanoparticles that were reconstituted into solid spheres (70-100 μm) by spray drying. The surface morphology of sintered and unsintered agglomerates was examined by FE-SEM prior to deposition by atmospheric plasma spraying using two gun configurations, one with a lengthened barrel and one with water cooling. YSZ coating cross-sections were examined by optical and electron microscopy, revealing details at the micro and nano scale. The results show that the unsintered agglomerates, which were successfully deposited using both spray guns, are favorable for developing bimodal coating structures with fine grains and porous nano zones.
