Effect of starch filler content and sintering temperature on the processing of porous 3y-zro2 ceramics

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

JOURNAL OF MATERIALS PROCESSING TECHNOLOGY

ELSEVIER SCIENCE SA

Año: 2009 vol. 209 p. 590 - 598

0924-0136

A direct casting processwas used to produce porous 3Y–ZrO2 ceramics using starch as a fugitive filler and binder. The compositions with lowadditions of starch had higher porosity than the volume fraction of starch initially in the green body (Xst), whereas, the compositions with high amounts of starch produced lower porosity than the predicted value. The well ordered structure consisted of spherical pores of 8–10_mdiameter, retained from the original starch particles, connected by channels. The interconnection between poreswas dependent on the volume fraction of starch incorporated, as well as on the sintering temperature. Pore interconnection was observed for all the compositions sintered at 1000–1300 ◦C. Increasing the sintering temperature to 1400–1500 ◦C produced a marked dependence of the open to total porosity ratio on Xst. For a high porosity material, a bimodal channel size distribution was found at 1400 and 1500 ◦C. The primary pore channel diameterwas 0.7_mand the secondary onewas close to 4_m. As the sintering temperature increased, the volume of the connecting channels decreased; at 1500 ◦C only a minor volume of the larger channels was found.