CONICET | Buscador de Institutos y Recursos Humanos

Porous yttria stabilized zirconia (YSZ) substrates with volume fractions of porosity ranging from 28.9 to 53 volume % were developed using starch as a fugitive additive. Concentrated aqueous YSZ slips with different amounts of starch and an acrylic latex binder were prepared. The influence of the volume fraction of starch and sintering temperature on the sintering behavior and final microstructure were investigated. In addition, details of the microstructure were observed by scanning electron microscopy (SEM). The porosities were above those predicted for all the starch contents examined. Two kinds of pores were observed in the sintered tapes: large pores created by the starch particles with lengths between 15 and 80 mm and smaller pores in the matrix with lengths between 0.6 and 3.8 mm. The total porosity and the percentage of open porosity in the sintered tapes could be controlled by the volume fraction of added starch as well as by the sintering temperature. The wall surface of the pores left by the starch and the inner shells of YSZ, reached a lower densification than the rest of the YSZ matrix. The top surface of the sintered tapes had a greater porosity than the bottom one.