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Dispersion of Zirconium Diboride in an Aqueous, High‐Solids Paste
Author(s) -
Huang Tieshu,
Hilmas Gregory E.,
Fahrenholtz William G.,
Leu Ming C.
Publication year - 2007
Publication title -
international journal of applied ceramic technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.4
H-Index - 57
eISSN - 1744-7402
pISSN - 1546-542X
DOI - 10.1111/j.1744-7402.2007.02157.x
Subject(s) - dispersant , zirconium diboride , materials science , aqueous solution , dispersion (optics) , zirconium , isoelectric point , chemical engineering , composite material , viscosity , layer (electronics) , metallurgy , organic chemistry , chemistry , physics , optics , enzyme , engineering
The dispersion of ZrB 2 particles was investigated. In aqueous systems, the surface of ZrB 2 consists of a thin layer of ZrO 2 that controls the surface chemistry and surface charge. Measurements showed that the ZrB 2 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 ZrB 2 by as much as 60 mV to −110 mV. Viscosity measurements were used to optimize dispersant concentrations. High‐solids loading (∼45 vol.% ZrB 2 ) 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 ZrB 2 .