Consolidation behavior of high-performance ceramic suspensions

Journal Article · Thu Feb 01 04:00:00 EST 1990 · Journal of the American Ceramic Society; (USA)

DOI:https://doi.org/10.1111/j.1151-2916.1990.tb06494.x· OSTI ID:6786175

Novich, B E ^[1]; Pyatt, D H ^[2]

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1. Ceramics Process System Corp., Milford, MA (US)
2. Massachusetts Univ., Amherst, MA (USA). Dept. of Civil Engineering

Colloidal processing has been shown to produce low defect and uniform ceramic microstructures from submicrometer ceramic powders. These concepts were applied to colloidal pressing to determine critical design relationships for uniaxial consolidation of dense and uniform green bodies from colloidal suspensions. Carefully controlled constant rate of strain consolidation experiments were carried out using alumina in water. The compression index decreased from 0.143 for a poorly dispersed alumina system to 0.077 for a well-dispersed alumina suspension compression curve, indicating that the well-dispersed system is stiffer in consolidation. The compression curves showed that, as the degree of dispersion decreases, increased consolidation stresses are required to achieve a given particle packing density. The compression index increased with increasing strain rate for well-dispersed alumina suspensions. Permeability through the sample ranged from 3 {times} 10{sup {minus} 8} to 4 {times} 10{sup {minus} 7} cm/s, decreasing with decreasing void ratio during consolidation. Well-dispersed samples gave lower permeabilities than did poorly dispersed samples over a given consolidation increment. Coefficients of consolidation were nonconstant over the experimental effective stress range, invalidating the general solution to the linear consolidation equation. An approximate incremental solution was applied which indicated rapid pressing cycles are possible by starting with a suspension having a high solids concentration. Application of this consolidation data to nonlinear consolidation models is recommended for more exact prediction of consolidation time.

• OSTI ID: 6786175
• Journal Information: Journal of the American Ceramic Society; (USA), Journal Name: Journal of the American Ceramic Society; (USA) Vol. 73:2; ISSN JACTA; ISSN 0002-7820
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360201 -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CERAMICS
CHALCOGENIDES
COLLOIDS
CRYSTAL STRUCTURE
DISPERSIONS
MICROSTRUCTURE
MIXTURES
OXIDES
OXYGEN COMPOUNDS
SOLID SOLUTIONS
SOLUTIONS