LIU Xuejian, HUANG Liping, FU Xiren,  Gu Hongchen

( Shanghai Institute of Ceramic, Chinese Academy of Sciences; East China University of Science & Technology)

Abstract: In this paper, the optimum condit ions of preparation of highly concent rated silicon ni tride aqueous suspension was investigated by sedimentation, Zeta potential and rheological measurement .The results indicated that the isoelect ric point of the silico n nitride powders is at the pH vallue of 4 .2, and the v alue of Zeta po tential is up to it s maximum near pH =11 .The int roduct ion of dispersant increases Zeta potential in magnitude and improves the f luidi ty efficiently.The optimum amount of dispersant is at the ranges f rom 1 .0 to 1 .2w t %w hich is independent on the solid volume fraction of suspension .A milling t ime of 8h is appropriate while longer time is det rimental to obtain bet ter fluidity .

Keywords: silicon nitride, suspension, preparation optimization