ZHANG Yanli ¹, YIN Bo ², ZHANG Xiaoqing ¹, GU Yiheng ¹, CHEN Han ¹, GUO Lucun ¹

(1. College of Materials Science and Engineering, Nanjing University of Technology, Nanjing 210009, Jiangsu, China; 2. Yixing Morgan Thermal Ceramics Co., Ltd., Yixing 214222, Jiangsu, China)

Abstract: The dispersion and stability of Al₂O₃ suspensions and SiC suspensions have been investigated by measuring zeta potential and rheology at pH 3.0–12.0. Based on the above experiment, the rheological properties of the binary suspensions of Al₂O₃/SiC were tested as a function of pH. It was found that the dispersion stability of the binary suspensions was strongly dependent on pH. At pH≤3.0, the binary system with opposite charged Al₂O₃and SiC particles was well-dispersed and not flocculated. At pH 3.0–9.0, similar to the unary SiC suspensions, the Al₂O₃/SiC binary suspension was strongly flocculated. At pH 9.0–12.0, the stability of the SiC component seemed to dominate the overall rheological behavior of the Al₂O₃/SiC binary suspensions, and Al₂O₃/SiC binary system and SiC suspensions were well-dispersed.

Key words: alumina; silicon carbide; pH; binary suspensions; rheology