Boehmite coating as a consolidation and forming aid in aqueous silicon nitride processing

Journal Article · Mon May 01 04:00:00 EDT 1995 · Journal of the American Ceramic Society

DOI:https://doi.org/10.1111/j.1151-2916.1995.tb08478.x· OSTI ID:69622

Shih, W H; Pwu, L L; Tseng, A A ^[1]

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1. Drexel Univ., Philadelphia, PA (United States)

Silicon nitride powders were coated by boehmite via a sol-gel process to improve the consolidation and forming of aqueous silicon nitride suspensions. The coated silicon nitride suspensions had a significantly higher solids loading than the pore silicon nitride in water. Viscosity measurements and centrifugation showed that the coating changed the long-range interaction between the silicon nitride particles, whereas the pressure nitration study indicated that the oxide coating modified the short-range interaction at particle contacts. Preliminary rheological studies indicated that at pH 3, the boehmite-coated silicon nitride suspensions can gel, as indicated by a wide linear viscoelastic region in dynamic rheological tests. The gelation of coated silicon nitride at pH 3 offers the potential for net-shape forming. Their study establishes a water-based green body consolidation and forming technique of silicon nitride without polymeric additives or organic solvents.

• Sponsoring Organization: USDOE
• OSTI ID: 69622
• Journal Information: Journal of the American Ceramic Society, Journal Name: Journal of the American Ceramic Society Journal Issue: 5 Vol. 78; ISSN 0002-7820; ISSN JACTAW
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ADDITIVES
ALUMINIUM COMPOUNDS
COATINGS
GELATION
OXIDES
PARTICULATES
RHEOLOGY
SILICON NITRIDES
SLURRIES
SOL-GEL PROCESS
VISCOSITY