Emulsion Precipitation of Yttria‐Stabilized Zirconia for Plasma Spray Coatings

Abstract

Chemically uniform, high‐purity, yttria‐stabilized zirconia (YSZ) powders were prepared by emulsion hydrolysis of the metal alkoxides, acetates, and mixtures of alkoxides and acetates. Both the morphology and particle size of the powders can be controlled by varying the hydrolysis conditions. Spherical or granular powders with particle sizes ranging from submicrometer to a few hundred micrometers were obtained. X‐ray diffraction and EDX results showed that yttria was evenly distributed throughout the zirconia particles. The crystalline phase of the powders after calcination at 800°C was 100% nontransformable tetragonal. The powders were successfully sprayed by a plasma coating technique on stainless steel coupons, and the coatings were evaluated.