CHARACTERIZATION OF POROUS ZIRCONIA PREPARED FROM POTATO STARCH

L.B. GARRIDO,; M.P. ALBANO,; L.A. GENOVA; K.P. PLUCKNETT

Guarujá, SP, Brasil

Congreso; 53¨¬ CONGRESSO BRASILEIRO DE CERAMICA,; 2009

Porous zirconia (3 mol% yttria stabilized ZrO2) was processed by the starch consolidation method using potato starch as a pore forming agent and binder. Various ZrO2-starch compositions with volume fractions of starch (relative to the volume of solids) between 0.44 and 0.68 were prepared. Concentrated aqueous suspensions (near to 50 vol %) of the different compositions were consolidated in a plastic mold by controlled heating. The effects of the volume fraction of starch in the green body Xst and sintering temperatures (1000-1500 ºC) on relative density and microstructure of sintered bodies were examined by scanning electron microscopy SEM and Hg porosimetry. The microstructure consisted of large spherical pores left by the starch granules, having diameters of 50 um or higher and connected by channels of approximately 5 um size. Total porosity of products sintered at 1500 ºC increased slightly from 49 to 54 vol. % for Xst of 0.23 and 0.54, respectively. The porosity was completely open for the different Xst values.