Synthesis of YSZ powders with controlled properties by the CDJP method

Abstract

In this work, YSZ powders were synthesized by the controlled double-jet precipitation at constant pH values in the range from 3 to 8. It has been shown that weakly bound floccule-like particles with diffuse boundaries, obtained at pH 3, 7 and 8, strongly agglomerate during drying and form large particles of irregular shape. The dense spherical aggregates of zirconium hydroxide are formed only at CDJP at pH 4 and 5 due to the layer-by-layer buildup of primary particles on the surface of the aggregates. These dense aggregates capture less salt, do not undergo additional agglomeration during drying and retain a low size dispersion. YSZ powder obtained at pH 5 has a high bulk density and fluidity, as well as a narrower particle size distribution than conventional thermal spray powders. The use of this powder resulted in the formation of a uniform coating with high adhesion, uniform porosity and reduced roughness.