Dispersion of Zirconium Diboride in an Aqueous, High-Solids Paste

• Published in: International journal of applied ceramic technology Vol. 4; no. 5; pp. 470 - 479
• Main Authors: Huang, Tieshu, Hilmas, Gregory E., Fahrenholtz, William G., Leu, Ming C.
• Format: Journal Article
• Language: English
• Published: Malden, USA Blackwell Publishing Inc 01.10.2007
• ISSN: 1546-542X; 1744-7402
• DOI: 10.1111/j.1744-7402.2007.02157.x

The dispersion of ZrB2 particles was investigated. In aqueous systems, the surface of ZrB2 consists of a thin layer of ZrO2 that controls the surface chemistry and surface charge. Measurements showed that the ZrB2 had an isoelectric point of pH=4.7 and a maximum ζ potential of −50 mV at pH=9. The addition of a dispersant, either an ionic ammonium polyacrylate or a nonionic alkoxylated polyether, increased the ζ potential of ZrB2 by as much as 60 mV to −110 mV. Viscosity measurements were used to optimize dispersant concentrations. High‐solids loading (∼45 vol.% ZrB2) aqueous pastes were prepared with two different dispersants. The pastes had viscosities of 40–50 Pa·s which was acceptable for extrusion, and were used to fabricate three‐dimensional components from ZrB2.