Consolidation of colloidal suspensions

Conference · Wed Aug 01 04:00:00 EDT 1990

OSTI ID:6550798

Shih, Wei-Heng; Kim, Seong Il; Shih, Wan Y; Aksay, I A ^[1]; Schilling, C H ^[2]

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1. Washington Univ., Seattle, WA (USA)
2. Washington Univ., Seattle, WA (USA) Pacific Northwest Lab., Richland, WA (USA)

A key step in the processing of ceramics is the consolidation of powders into engineered shapes. Colloidal processing uses solvents (usually water) and dispersants to break up powder agglomerates in suspension and thereby reduce the pore size in a consolidated compact. However, agglomeration and particle rearrangement leading to pore enlargement can still occur during drying. Therefore, it is beneficial to consolidate the compact as densely as possible during the suspension stage. The consolidation techniques of pressure filtration and centrifugation were studied and the results are reported in this paper. In particular, the steady-state pressure- density relationship was studied, and information was obtained regarding the consolidation process, the microstructure, and the average density profile of consolidated cakes. Recently, we performed Monte Carlo simulations on a cluster-cluster aggregation model with restructuring, and found the exponential relationship between pressure and density is indeed the result of the breaking up of the fractal structural units. Furthermore, we calculated density profiles from the bottom to the top of the consolidated cakes by solving the local static force balance equation in the continuum particulate network. 11 refs., 3 figs.

• Research Organization: Pacific Northwest Lab., Richland, WA (USA)
• Sponsoring Organization: DOE/ER
• DOE Contract Number: AC06-76RL01830
• OSTI ID: 6550798
• Report Number(s): PNL-SA-18319; CONF-900466--88; ON: DE91000415
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360201* -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
CENTRIFUGATION
CERAMICS
COLLOIDS
COMPACTING
DENSITY
DISPERSIONS
FILTRATION
PHYSICAL PROPERTIES
POWDERS
SEPARATION PROCESSES
SUSPENSIONS