Rheological properties of concentrated, nonaqueous silicon nitride suspensions

Journal Article · Sun Dec 01 04:00:00 EST 1996 · Journal of the American Ceramic Society

DOI:https://doi.org/10.1111/j.1151-2916.1996.tb08074.x· OSTI ID:422705

Bergstroem, L ^[1]

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1. Inst. for Surface Chemistry, Stockholm (Sweden)

The rheological properties of nonaqueous silicon nitride powder suspensions have been investigated using steady shear and viscoelastic measurements. The polymeric dispersant, Hypermer KD-3, adsorbed strongly on the powder surfaces, and colloidally stable, fluid suspensions up to a volume fraction of {Phi} = 0.50 could be prepared. The concentrated suspensions all displayed a shear thinning behavior which could be modeled using the high shear form of the Cross equation. The viscoelastic response at high concentrations was dominated by particle interactions, probably due to interpenetration of the adsorbed polymer layers, and a thickness of the adsorbed Hypermer KD-3 layer, {Delta} {approx} 10 nm, was estimated. The volume fraction dependences of the high shear viscosity of three different silicon nitride powders were compared and the differences, analyzed by using a modified Krieger-Dougherty model, were related to effective volume effects and the physical characteristics of the powders. The significantly lower maximum volume fraction, {Phi}{sub m} = 0.47, of the SN E-10 powder was referred to the narrow particle size distribution and the possibility of an unfavorable particle morphology.

• Sponsoring Organization: Swedish National Board for Technical Development, Stockholm (Sweden)
• OSTI ID: 422705
• Journal Information: Journal of the American Ceramic Society, Journal Name: Journal of the American Ceramic Society Journal Issue: 12 Vol. 79; ISSN 0002-7820; ISSN JACTAW
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CASTING
CONCENTRATION RATIO
DECALIN
EXPERIMENTAL DATA
MATHEMATICAL MODELS
MORPHOLOGY
PARTICLE SIZE
POLYMERS
POWDERS
SHEAR PROPERTIES
SILICON NITRIDES
SLURRIES
VISCOSITY