Dip-coating of 8YSZ nanocrystalline particles on NiO-YSZ substrate

In this study, 8 mol% yttria-stabilized zirconia (8YSZ)-agglomerated particles were dispersed in de-ionized water using different weights of Tiron. The results of viscosity and sedimentation measurements of each suspension were evaluated and the optimum amount of Tiron was selected. The most stable suspension was prepared for dip-coating. The substrate was prepared by mixing NiO and YSZ powders and then pressed and pre-sintered at 1050℃. The effect of saturated and unsaturated substrates on morphology and thickness of films were investigated. The thickness of YSZ films with different withdrawn speeds and dip-times were calculated. Also, the morphologies of deposited films were characterized by scanning electron microscopy. The above experimental results showed that by adjusting pH about 10, the view point of rheological behaviour, the optimum dispersant was 0.8% and the suspension containing 0.8% Tiron had the lowest viscosity. Finally, the obtained layers from dip-coating method represented that the films deposited on saturated substrate were crack-free and homogeneous when compared to unsaturated substrates. (author)