Abstract

ESPARZA-PONCE, H. E; REYES-ROJAS, A  and  MIKI YOSHIDA, M. SPHERICAL CALCIA STABILIZED ZIRCONIA POWDERS OBTAINED BY SPRAY PYROLYSIS . Rev. LatinAm. Met. Mat. [online]. 2001, vol.21, n.2, pp.3-8. ISSN 0255-6952.

Physical and chemical properties of ceramic powders are highly dependent on the morphology and chemical composition of the precursor powders. Therefore, properties of ceramic powders are expecting to be improved by controlling the most important parameters of morphology such as composition of precursors, temperature and airflow. Promising techniques to produce ceramic powders with controlled morphology are sol-gel, coprecipitation, and pyrolysis. Among these techniques, spray pyrolysis is one of the most suitable to control the morphology and the chemical composition of the particles, because the spray pyrolysis technique integrates the evaporation, precipitation, decomposition and sintering stage of powder synthesis into a single continuos process. Spherical powders were prepared from acetylacetonate of zirconium and acetate calcium hydrated solutions by pneumatic spray pyrolysis. The morphology and size of the powders change with variation of airflow, temperature, and solution concentration.

Keywords : Spray pyrolysis technique; ultrafine powders; precursor ceramics; zirconia and calcia.