CENTRO DE TECNOLOGIA DE RECURSOS MINERALES Y CERAMICA
Unidad Ejecutora - UE
Influence of starch type on characteristics of porous 3Y-ZrO2 prepared from a direct consolidation casting method
L. B. GARRIDO; M. P. ALBANO; L. A. GENOVA; K. P. PLUCKNETT
UNIV FED SAO CARLOS
Lugar: San Carlos; Año: 2010
Porous 3Y-ZrO2 ceramics were produced with a direct consolidation method using starch as a pore forming and binder agent. Concentrated aqueous 3Y- ZrO2 suspensions with two different types of starch, potato and corn, were prepared. The consolidation of the suspensions was performed in a covered plastic mold at 90 ºC for 30 min. The microstructure consisted of large nearly spherical pores connected by channels uniformly distributed in a dense zirconia matrix. The size and the shape of the pores were mainly controlled by the content and morphological characteristics of each type of starch granule. The total porosity of the compacts sintered at 1500 ºC slightly increased from 49 to 52 vol.% and 50 to 54 vol.% with increasing the volume fraction of starch in the green body (Xst) from 0.23 to 0.65, for corn and potato starches respectively. The porosity of the samples produced from potato starch was completely open for all the different Xst values, while for those prepared from corn starch pore interconnection was observed for Xst >50 vol.%. The more elongated pores with larger sizes of the potato starch contributed to the overlapping of pores in the sintered body. Potato starch yield products with larger pore size, higher porosity and openness of pore structure than those prepared with identical content of corn starch in the green body.