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 potential of −50 mV at pH=9. The addition of a dispersant, either an ionic ammonium polyacrylate or a nonionic alkoxylated polyether, increased the 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.
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Document Type: Research Article
Department of Materials Science & Engineering, 1870 Miner Circle, University of Missouri—Rolla Rolla, Missouri 65409-0050
Department of Mechanical and Aerospace Engineering, 1870 Miner Circle, University of Missouri—Rolla Rolla, Missouri 65409-0050
Publication date: 2007-10-01